Programs & Examples On #Memory management

Run the command java -X and you will get a list of all -X options:

C:\Users\Admin>java -X
-Xmixed           mixed mode execution (default)
-Xint             interpreted mode execution only
-Xbootclasspath:<directories and zip/jar files separated by ;>
                      set search path for bootstrap classes and resources
-Xbootclasspath/a:<directories and zip/jar files separated by ;>
                      append to end of bootstrap class path
-Xbootclasspath/p:<directories and zip/jar files separated by ;>
                      prepend in front of bootstrap class path
-Xdiag            show additional diagnostic messages
-Xnoclassgc       disable class garbage collection
-Xincgc           enable incremental garbage collection
-Xloggc:<file>    log GC status to a file with time stamps
-Xbatch           disable background compilation
-Xms<size>        set initial Java heap size.........................
-Xmx<size>        set maximum Java heap size.........................
-Xss<size>        set java thread stack size
-Xprof            output cpu profiling data
-Xfuture          enable strictest checks, anticipating future default
-Xrs              reduce use of OS signals by Java/VM (see documentation)
-Xcheck:jni       perform additional checks for JNI functions
-Xshare:off       do not attempt to use shared class data
-Xshare:auto      use shared class data if possible (default)
-Xshare:on        require using shared class data, otherwise fail.
-XshowSettings    show all settings and continue
-XshowSettings:all         show all settings and continue
-XshowSettings:vm          show all vm related settings and continue
-XshowSettings:properties  show all property settings and continue
-XshowSettings:locale      show all locale related settings and continue

The -X options are non-standard and subject to change without notice.

I hope this will help you understand Xms, Xmx as well as many other things that matters the most. :)

wordpress users add line:

@ini_set('memory_limit', '-1');

in wp-settings.php which you can find in the wordpress installed root folder

All procedure at once. Based on @Till Schäfer answer.

In KB...

jstat -gc $(ps axf | egrep -i "*/bin/java *" | egrep -v grep | awk '{print $1}') | tail -n 1 | awk '{split($0,a," "); sum=(a[3]+a[4]+a[6]+a[8]+a[10]); printf("%.2f KB\n",sum)}'

In MB...

jstat -gc $(ps axf | egrep -i "*/bin/java *" | egrep -v grep | awk '{print $1}') | tail -n 1 | awk '{split($0,a," "); sum=(a[3]+a[4]+a[6]+a[8]+a[10])/1024; printf("%.2f MB\n",sum)}'

"Awk sum" reference:

 a[1] - S0C
 a[2] - S1C
 a[3] - S0U
 a[4] - S1U
 a[5] - EC
 a[6] - EU
 a[7] - OC
 a[8] - OU
 a[9] - PC
a[10] - PU
a[11] - YGC
a[12] - YGCT
a[13] - FGC
a[14] - FGCT
a[15] - GCT

Used for "Awk sum":

a[3] -- (S0U) Survivor space 0 utilization (KB).
a[4] -- (S1U) Survivor space 1 utilization (KB).
a[6] -- (EU) Eden space utilization (KB).
a[8] -- (OU) Old space utilization (KB).
a[10] - (PU) Permanent space utilization (KB).

[Ref.: https://docs.oracle.com/javase/7/docs/technotes/tools/share/jstat.html ]

Thanks!

NOTE: Works to OpenJDK!

FURTHER QUESTION: Wrong information?

If you check memory usage with the ps command, you will see that the java process consumes much more...

ps -eo size,pid,user,command --sort -size | egrep -i "*/bin/java *" | egrep -v grep | awk '{ hr=$1/1024 ; printf("%.2f MB ",hr) } { for ( x=4 ; x<=NF ; x++ ) { printf("%s ",$x) } print "" }' | cut -d "" -f2 | cut -d "-" -f1

UPDATE (2021-02-16):

According to the reference below (and @Till Schäfer comment) "ps can show total reserved memory from OS" (adapted) and "jstat can show used space of heap and stack" (adapted). So, we see a difference between what is pointed out by the ps command and the jstat command.

According to our understanding, the most "realistic" information would be the ps output since we will have an effective response of how much of the system's memory is compromised. The command jstat serves for a more detailed analysis regarding the java performance in the consumption of reserved memory from OS.

[Ref.: http://www.openkb.info/2014/06/how-to-check-java-memory-usage.html ]

R has gotten to the point where the OS cannot allocate it another 75.1Mb chunk of RAM. That is the size of memory chunk required to do the next sub-operation. It is not a statement about the amount of contiguous RAM required to complete the entire process. By this point, all your available RAM is exhausted but you need more memory to continue and the OS is unable to make more RAM available to R.

Potential solutions to this are manifold. The obvious one is get hold of a 64-bit machine with more RAM. I forget the details but IIRC on 32-bit Windows, any single process can only use a limited amount of RAM (2GB?) and regardless Windows will retain a chunk of memory for itself, so the RAM available to R will be somewhat less than the 3.4Gb you have. On 64-bit Windows R will be able to use more RAM and the maximum amount of RAM you can fit/install will be increased.

If that is not possible, then consider an alternative approach; perhaps do your simulations in batches with the n per batch much smaller than N. That way you can draw a much smaller number of simulations, do whatever you wanted, collect results, then repeat this process until you have done sufficient simulations. You don't show what N is, but I suspect it is big, so try smaller N a number of times to give you N over-all.

I encountered a similar problem, and I used 2 flash drives as 'ReadyBoost'. The two drives gave additional 8GB boost of memory (for cache) and it solved the problem and also increased the speed of the system as a whole. To use Readyboost, right click on the drive, go to properties and select 'ReadyBoost' and select 'use this device' radio button and click apply or ok to configure.

Your program crashes because it used memory that does not belong to you. It may be used by someone else or not - if you are lucky you crash, if not the problem may stay hidden for a long time and come back and bite you later.

As far as malloc/free implementation goes - entire books are devoted to the topic. Basically the allocator would get bigger chunks of memory from the OS and manage them for you. Some of the problems an allocator must address are:

• How to get new memory
• How to store it - ( list or other structure, multiple lists for memory chunks of different size, and so on )
• What to do if the user requests more memory than currently available ( request more memory from OS, join some of the existing blocks, how to join them exactly, ... )
• What to do when the user frees memory
• Debug allocators may give you bigger chunk that you requested and fill it some byte pattern, when you free the memory the allocator can check if wrote outside of the block ( which is probably happening in your case) ...

1) Is the synthesize within @implementation block?

2) Should you refer to self.classA = [[ClassA alloc] init]; and self.classA.downloadUrl = @"..." instead of plain classA?

3) In your myApp.m file you need to import ClassA.h, when it's missing it will default to a number, or pointer? (in C variables default to int if not found by compiler):

#import "ClassA.h".

For anyone who is looking for solutions here, I had a similar issue with C++: malloc(): smallbin double linked list corrupted:

This was due to a function not returning a value it was supposed to.

std::vector<Object> generateStuff(std::vector<Object>& target> {
  std::vector<Object> returnValue;
  editStuff(target);
  // RETURN MISSING
}

Don't know why this was able to compile after all. Probably there was a warning about it.

Because /usr/bin/time is not present in many modern distributions (Bash built-in time instead), you can use Busybox time implementation with -v argument:

busybox time -v uname -r

It's output is similar to GNU time output. Busybox is pre-installed in most Linux distros (Debian, Ubuntu, etc.). If you using Arch Linux, you can install it with:

sudo pacman -S busybox

It works because the stack has not been altered (yet) since a was put there. Call a few other functions (which are also calling other functions) before accessing a again and you will probably not be so lucky anymore... ;-)

In RStudio, to increase:

file.edit(file.path("~", ".Rprofile"))

then in .Rprofile type this and save

invisible(utils::memory.limit(size = 60000))

To decrease: open .Rprofile

invisible(utils::memory.limit(size = 30000))

save and restart RStudio.

You need to use the Disposable Pattern like this:

private bool _disposed = false;

protected virtual void Dispose(bool disposing)
{
    if (!_disposed)
    {
        if (disposing)
        {
            // Dispose any managed objects
            // ...
        }

        // Now disposed of any unmanaged objects
        // ...

        _disposed = true;
    }
}

public void Dispose()
{
    Dispose(true);
    GC.SuppressFinalize(this);  
}

// Destructor
~YourClassName()
{
    Dispose(false);
}

As well as the more general memory management techniques given in the answers above, I always try to reduce the size of my objects as far as possible. For example, I work with very large but very sparse matrices, in other words matrices where most values are zero. Using the 'Matrix' package (capitalisation important) I was able to reduce my average object sizes from ~2GB to ~200MB as simply as:

my.matrix <- Matrix(my.matrix)

The Matrix package includes data formats that can be used exactly like a regular matrix (no need to change your other code) but are able to store sparse data much more efficiently, whether loaded into memory or saved to disk.

Additionally, the raw files I receive are in 'long' format where each data point has variables x, y, z, i. Much more efficient to transform the data into an x * y * z dimension array with only variable i.

Know your data and use a bit of common sense.

My explanation uses elementary building blocks that helped me to understand. Note I am leveraging @Deepak Goyal's answer above since he provided clarity:

We were given a logical 32-bit address space (i.e. We have a 32 bit computer)

Consider a system with a 32-bit logical address space

• This means that every memory address can be 32 bits long.
• "A 32-bit entry can point to one of 2^32 physical page frames"[2], stated differently,
• "A 32-bit register can store 2^32 different values"

We were also told that

each page size is 4 KB

• 1 KB (kilobyte) = 1 x 1024 bytes = 2^10 bytes
• 4 x 1024 bytes = 2^2 x 2^10 bytes => 4 KB (i.e. 2^12 bytes)
• The size of each page is thus 4 KB (Kilobytes NOT kilobits).

As Depaak said, we calculate the number of pages in the page table with this formula:

Num_Pages_in_PgTable = Total_Possible_Logical_Address_Entries / page size 
Num_Pages_in_PgTable =         2^32                           /    2^12
Num_Pages_in_PgTable = 2^20 (i.e. 1 million) 

The authors go on to give the case where each entry in the page table takes 4 bytes. That means that the total size of the page table in physical memory will be 4MB:

Memory_Required_Per_Page = Size_of_Page_Entry_in_bytes x Num_Pages_in_PgTable
Memory_Required_Per_Page =           4                 x     2^20
Memory_Required_Per_Page =     4 MB (Megabytes)

So yes, each process would require at least 4MB of memory to run, in increments of 4MB.

Example

Now if a professor wanted to make the question a bit more challenging than the explanation from the book, they might ask about a 64-bit computer. Let's say they want memory in bits. To solve the question, we'd follow the same process, only being sure to convert MB to Mbits.

Let's step through this example.

Givens:

• Logical address space: 64-bit
• Page Size: 4KB
• Entry_Size_Per_Page: 4 bytes

Recall: A 64-bit entry can point to one of 2^64 physical page frames - Since Page size is 4 KB, then we still have 2^12 byte page sizes

• 1 KB (kilobyte) = 1 x 1024 bytes = 2^10 bytes
• Size of each page = 4 x 1024 bytes = 2^2 x 2^10 bytes = 2^12 bytes

How Many pages In Page Table?

`Num_Pages_in_PgTable = Total_Possible_Logical_Address_Entries / page size 
Num_Pages_in_PgTable =         2^64                            /    2^12
Num_Pages_in_PgTable =         2^52 
Num_Pages_in_PgTable =      2^2 x 2^50 
Num_Pages_in_PgTable =       4  x 2^50 `  

How Much Memory in BITS Per Page?

Memory_Required_Per_Page = Size_of_Page_Entry_in_bytes x Num_Pages_in_PgTable 
Memory_Required_Per_Page =   4 bytes x 8 bits/byte    x     2^52
Memory_Required_Per_Page =     32 bits                x   2^2 x 2^50
Memory_Required_Per_Page =     32 bits                x    4  x 2^50
Memory_Required_Per_Page =     128 Petabits

[2]: Operating System Concepts (9th Ed) - Gagne, Silberschatz, and Galvin

You can use pmap + awk.

Most likely, we're interested in the RSS memory which is the 3rd column in the last line of the example pmap output below (82564).

$ pmap -x <pid>

Address           Kbytes     RSS   Dirty Mode   Mapping

....

00007f9caf3e7000       4       4       4 r----  ld-2.17.so
00007f9caf3e8000       8       8       8 rw---  ld-2.17.so
00007fffe8931000     132      12      12 rw---    [ stack ]
00007fffe89fe000       8       8       0 r-x--    [ anon ]
ffffffffff600000       4       0       0 r-x--    [ anon ]
----------------  ------  ------  ------
total kB          688584   82564    9592

Awk is then used to extract that value.

$ pmap -x <pid> | awk '/total/ { print $4 "K" }'

The pmap values are in kilobytes. If we wanted it in megabytes, we could do something like this.

$ pmap -x <pid> | awk '/total/ { print $4 / 1024 "M" }'

To check if there is a GPU available:

torch.cuda.is_available()

If the above function returns False,

1. you either have no GPU,
2. or the Nvidia drivers have not been installed so the OS does not see the GPU,
3. or the GPU is being hidden by the environmental variable CUDA_VISIBLE_DEVICES. When the value of CUDA_VISIBLE_DEVICES is -1, then all your devices are being hidden. You can check that value in code with this line: os.environ['CUDA_VISIBLE_DEVICES']

If the above function returns True that does not necessarily mean that you are using the GPU. In Pytorch you can allocate tensors to devices when you create them. By default, tensors get allocated to the cpu. To check where your tensor is allocated do:

# assuming that 'a' is a tensor created somewhere else
a.device  # returns the device where the tensor is allocated

Note that you cannot operate on tensors allocated in different devices. To see how to allocate a tensor to the GPU, see here: https://pytorch.org/docs/stable/notes/cuda.html

You have to free() the allocated memory in exact reverse order of how it was allocated using malloc().

Note that You should free the memory only after you are done with your usage of the allocated pointers.

memory allocation for 1D arrays:

    buffer = malloc(num_items*sizeof(double));

memory deallocation for 1D arrays:

    free(buffer);

memory allocation for 2D arrays:

    double **cross_norm=(double**)malloc(150 * sizeof(double *));
    for(i=0; i<150;i++)
    {
        cross_norm[i]=(double*)malloc(num_items*sizeof(double));
    }

memory deallocation for 2D arrays:

    for(i=0; i<150;i++)
    {
        free(cross_norm[i]);
    }

    free(cross_norm);

This will delete the dataframe and will release the RAM/memory

del [[df_1,df_2]]
gc.collect()
df_1=pd.DataFrame()
df_2=pd.DataFrame()

the data-frame will be explicitly set to null

in the above statements

Firstly, the self reference of the dataframe is deleted meaning the dataframe is no longer available to python there after all the references of the dataframe is collected by garbage collector (gc.collect()) and then explicitly set all the references to empty dataframe.

more on the working of garbage collector is well explained in https://stackify.com/python-garbage-collection/

From this post:

To get the entire PC CPU and Memory usage:

using System.Diagnostics;

Then declare globally:

private PerformanceCounter theCPUCounter = 
   new PerformanceCounter("Processor", "% Processor Time", "_Total"); 

Then to get the CPU time, simply call the NextValue() method:

this.theCPUCounter.NextValue();

This will get you the CPU usage

As for memory usage, same thing applies I believe:

private PerformanceCounter theMemCounter = 
   new PerformanceCounter("Memory", "Available MBytes");

Then to get the memory usage, simply call the NextValue() method:

this.theMemCounter.NextValue();

For a specific process CPU and Memory usage:

private PerformanceCounter theCPUCounter = 
   new PerformanceCounter("Process", "% Processor Time",              
   Process.GetCurrentProcess().ProcessName);

where Process.GetCurrentProcess().ProcessName is the process name you wish to get the information about.

private PerformanceCounter theMemCounter = 
   new PerformanceCounter("Process", "Working Set",
   Process.GetCurrentProcess().ProcessName);

where Process.GetCurrentProcess().ProcessName is the process name you wish to get the information about.

Note that Working Set may not be sufficient in its own right to determine the process' memory footprint -- see What is private bytes, virtual bytes, working set?

To retrieve all Categories, see Walkthrough: Retrieving Categories and Counters

The difference between Processor\% Processor Time and Process\% Processor Time is Processor is from the PC itself and Process is per individual process. So the processor time of the processor would be usage on the PC. Processor time of a process would be the specified processes usage. For full description of category names: Performance Monitor Counters

An alternative to using the Performance Counter

Use System.Diagnostics.Process.TotalProcessorTime and System.Diagnostics.ProcessThread.TotalProcessorTime properties to calculate your processor usage as this article describes.

If you can make an approximation of the number of items that will be there at the end, use the overload of the List constuctor that takes count as a parameter. You will save some expensive List duplications. Otherwise you have to pay for it.

For numpy arrays, getsizeof doesn't work - for me it always returns 40 for some reason:

from pylab import *
from sys import getsizeof
A = rand(10)
B = rand(10000)

Then (in ipython):

In [64]: getsizeof(A)
Out[64]: 40

In [65]: getsizeof(B)
Out[65]: 40

Happily, though:

In [66]: A.nbytes
Out[66]: 80

In [67]: B.nbytes
Out[67]: 80000

You don't need to use del to delete instances in the first place. Once the last reference to an object is gone, the object will be garbage collected. Maybe you should tell us more about the full problem.

Why do you need -Xms768 (small heap must be at least 768...)?

That means any java process (search in eclipse) will start with 768m memory allocated, doesn't that? That is why your eclipse isn't able to start properly.

Try -Xms16 -Xmx2048m, for instance.

I recommend Dowser. It is very easy to setup, and you need zero changes to your code. You can view counts of objects of each type through time, view list of live objects, view references to live objects, all from the simple web interface.

# memdebug.py

import cherrypy
import dowser

def start(port):
    cherrypy.tree.mount(dowser.Root())
    cherrypy.config.update({
        'environment': 'embedded',
        'server.socket_port': port
    })
    cherrypy.server.quickstart()
    cherrypy.engine.start(blocking=False)

You import memdebug, and call memdebug.start. That's all.

I haven't tried PySizer or Heapy. I would appreciate others' reviews.

UPDATE

The above code is for CherryPy 2.X, CherryPy 3.X the server.quickstart method has been removed and engine.start does not take the blocking flag. So if you are using CherryPy 3.X

# memdebug.py

import cherrypy
import dowser

def start(port):
    cherrypy.tree.mount(dowser.Root())
    cherrypy.config.update({
        'environment': 'embedded',
        'server.socket_port': port
    })
    cherrypy.engine.start()

I think many other people have given you mostly correct answers on this matter.

One detail that has been missed, however, is that the "heap" should in fact probably be called the "free store". The reason for this distinction is that the original free store was implemented with a data structure known as a "binomial heap." For that reason, allocating from early implementations of malloc()/free() was allocation from a heap. However, in this modern day, most free stores are implemented with very elaborate data structures that are not binomial heaps.

In addition to @JesperFyhrKnudsen's answer and @MathiasLykkegaardLorenzen's comment, you'd better dispose the returned Process after using it.

So, In order to dispose the Process, you could wrap it in a using scope or calling Dispose on the returned process (proc variable).

1. using scope:

   var memory = 0.0;
   using (Process proc = Process.GetCurrentProcess())
   {
       // The proc.PrivateMemorySize64 will returns the private memory usage in byte.
       // Would like to Convert it to Megabyte? divide it by 2^20
          memory = proc.PrivateMemorySize64 / (1024*1024);
   }
   

2. Or Dispose method:

   var memory = 0.0;
   Process proc = Process.GetCurrentProcess();
   memory = Math.Round(proc.PrivateMemorySize64 / (1024*1024), 2);
   proc.Dispose();
   

Now you could use the memory variable which is converted to Megabyte.

PHP's config can be set in multiple places:

1. master system php.ini (usually in /etc somewhere)
2. somewhere in Apache's configuration (httpd.conf or a per-site .conf file, via php_value)
3. CLI & CGI can have a different php.ini (use the command php -i | grep memory_limit to check the CLI conf)
4. local .htaccess files (also php_value)
5. in-script (via ini_set())

In PHPinfo's output, the "Master" value is the compiled-in default value, and the "Local" value is what's actually in effect. It can be either unchanged from the default, or overridden in any of the above locations.

Also note that PHP generally has different .ini files for command-line and webserver-based operation. Checking phpinfo() from the command line will report different values than if you'd run it in a web-based script.

"variables declared implicitly" are properties of the global object, so delete works on them like it works on any property. Variables declared with var are indestructible.

For building containers you obviously want to use one of the standard containers (such as a std::vector). But this is a perfect example of the things you need to consider when your object contains RAW pointers.

If your object has a RAW pointer then you need to remember the rule of 3 (now the rule of 5 in C++11).

• Constructor
• Destructor
• Copy Constructor
• Assignment Operator
• Move Constructor (C++11)
• Move Assignment (C++11)

This is because if not defined the compiler will generate its own version of these methods (see below). The compiler generated versions are not always useful when dealing with RAW pointers.

The copy constructor is the hard one to get correct (it's non trivial if you want to provide the strong exception guarantee). The Assignment operator can be defined in terms of the Copy Constructor as you can use the copy and swap idiom internally.

See below for full details on the absolute minimum for a class containing a pointer to an array of integers.

Knowing that it is non trivial to get it correct you should consider using std::vector rather than a pointer to an array of integers. The vector is easy to use (and expand) and covers all the problems associated with exceptions. Compare the following class with the definition of A below.

class A
{ 
    std::vector<int>   mArray;
    public:
        A(){}
        A(size_t s) :mArray(s)  {}
};

Looking at your problem:

A* arrayOfAs = new A[5];
for (int i = 0; i < 5; ++i)
{
    // As you surmised the problem is on this line.
    arrayOfAs[i] = A(3);

    // What is happening:
    // 1) A(3) Build your A object (fine)
    // 2) A::operator=(A const&) is called to assign the value
    //    onto the result of the array access. Because you did
    //    not define this operator the compiler generated one is
    //    used.
}

The compiler generated assignment operator is fine for nearly all situations, but when RAW pointers are in play you need to pay attention. In your case it is causing a problem because of the shallow copy problem. You have ended up with two objects that contain pointers to the same piece of memory. When the A(3) goes out of scope at the end of the loop it calls delete [] on its pointer. Thus the other object (in the array) now contains a pointer to memory that has been returned to the system.

The compiler generated copy constructor; copies each member variable by using that members copy constructor. For pointers this just means the pointer value is copied from the source object to the destination object (hence shallow copy).

The compiler generated assignment operator; copies each member variable by using that members assignment operator. For pointers this just means the pointer value is copied from the source object to the destination object (hence shallow copy).

So the minimum for a class that contains a pointer:

class A
{
    size_t     mSize;
    int*       mArray;
    public:
         // Simple constructor/destructor are obvious.
         A(size_t s = 0) {mSize=s;mArray = new int[mSize];}
        ~A()             {delete [] mArray;}

         // Copy constructor needs more work
         A(A const& copy)
         {
             mSize  = copy.mSize;
             mArray = new int[copy.mSize];

             // Don't need to worry about copying integers.
             // But if the object has a copy constructor then
             // it would also need to worry about throws from the copy constructor.
             std::copy(&copy.mArray[0],&copy.mArray[c.mSize],mArray);

         }

         // Define assignment operator in terms of the copy constructor
         // Modified: There is a slight twist to the copy swap idiom, that you can
         //           Remove the manual copy made by passing the rhs by value thus
         //           providing an implicit copy generated by the compiler.
         A& operator=(A rhs) // Pass by value (thus generating a copy)
         {
             rhs.swap(*this); // Now swap data with the copy.
                              // The rhs parameter will delete the array when it
                              // goes out of scope at the end of the function
             return *this;
         }
         void swap(A& s) noexcept
         {
             using std::swap;
             swap(this.mArray,s.mArray);
             swap(this.mSize ,s.mSize);
         }

         // C++11
         A(A&& src) noexcept
             : mSize(0)
             , mArray(NULL)
         {
             src.swap(*this);
         }
         A& operator=(A&& src) noexcept
         {
             src.swap(*this);     // You are moving the state of the src object
                                  // into this one. The state of the src object
                                  // after the move must be valid but indeterminate.
                                  //
                                  // The easiest way to do this is to swap the states
                                  // of the two objects.
                                  //
                                  // Note: Doing any operation on src after a move 
                                  // is risky (apart from destroy) until you put it 
                                  // into a specific state. Your object should have
                                  // appropriate methods for this.
                                  // 
                                  // Example: Assignment (operator = should work).
                                  //          std::vector() has clear() which sets
                                  //          a specific state without needing to
                                  //          know the current state.
             return *this;
         }   
 }

See here: Physical Vs Virtual Memory

Virtual memory is stored on the hard drive and is used when the RAM is filled. Physical memory is limited to the size of the RAM chips installed in the computer. Virtual memory is limited by the size of the hard drive, so virtual memory has the capability for more storage.

It is possible using sun.misc.Unsafe : see this great answer from @Peter Lawrey -> Is there a way to get a reference address?

Using its code for printAddresses() :

    public static void printAddresses(String label, Object... objects) {
    System.out.print(label + ": 0x");
    long last = 0;
    int offset = unsafe.arrayBaseOffset(objects.getClass());
    int scale = unsafe.arrayIndexScale(objects.getClass());
    switch (scale) {
    case 4:
        long factor = is64bit ? 8 : 1;
        final long i1 = (unsafe.getInt(objects, offset) & 0xFFFFFFFFL) * factor;
        System.out.print(Long.toHexString(i1));
        last = i1;
        for (int i = 1; i < objects.length; i++) {
            final long i2 = (unsafe.getInt(objects, offset + i * 4) & 0xFFFFFFFFL) * factor;
            if (i2 > last)
                System.out.print(", +" + Long.toHexString(i2 - last));
            else
                System.out.print(", -" + Long.toHexString( last - i2));
            last = i2;
        }
        break;
    case 8:
        throw new AssertionError("Not supported");
    }
    System.out.println();
}

I set up this test :

    //hashcode
    System.out.println("Hashcode :       "+myObject.hashCode());
    System.out.println("Hashcode :       "+System.identityHashCode(myObject));
    System.out.println("Hashcode (HEX) : "+Integer.toHexString(myObject.hashCode()));

    //toString
    System.out.println("toString :       "+String.valueOf(myObject));

    printAddresses("Address", myObject);

Here is the output :

Hashcode :       125665513
Hashcode :       125665513
Hashcode (HEX) : 77d80e9
toString :       java.lang.Object@77d80e9
Address: 0x7aae62270

Conclusion :

• hashcode != address
• toString = class@HEX(hashcode)

Typically for dynamic lists of items, you use a std::vector.

Generally I use memset or a loop for raw memory dynamic allocation, depending on how variable I anticipate that area of code to be in the future.

You shouldn't have to worry about the stack leaking memory (it is highly uncommon). The only time you can have the stack get out of control is with infinite (or really deep) recursion.

This is just the heap. Sorry, didn't read your question fully at first.

You need to run the JVM with the following command line argument.

-Xmx<ammount of memory>

Example:

-Xmx1024m

That will allow a max of 1GB of memory for the JVM.

We faced similar issue recently, In case if a process refers to a deleted file, the Inode shall not be released, so you need to check lsof /, and kill/ restart the process will release the inodes.

Correct me if am wrong here.

What you're asking is not possible. There is no mechanism in .Net that would set all references to some object to null.

And I think that the fact that you're trying to do this indicates some sort of design problem. You should probably think about the underlying problem and solve it in another way (the other answers here suggest some options).

What you describe for the second method only gives you a 1D array:

int *board = new int[10];

This just allocates an array with 10 elements. Perhaps you meant something like this:

int **board = new int*[4];
for (int i = 0; i < 4; i++) {
  board[i] = new int[10];
}

In this case, we allocate 4 int*s and then make each of those point to a dynamically allocated array of 10 ints.

So now we're comparing that with int* board[4];. The major difference is that when you use an array like this, the number of "rows" must be known at compile-time. That's because arrays must have compile-time fixed sizes. You may also have a problem if you want to perhaps return this array of int*s, as the array will be destroyed at the end of its scope.

The method where both the rows and columns are dynamically allocated does require more complicated measures to avoid memory leaks. You must deallocate the memory like so:

for (int i = 0; i < 4; i++) {
  delete[] board[i];
}
delete[] board;

I must recommend using a standard container instead. You might like to use a std::array<int, std::array<int, 10> 4> or perhaps a std::vector<std::vector<int>> which you initialise to the appropriate size.

No, you're not allocating memory for y->x twice.

Instead, you're allocating memory for the structure (which includes a pointer) plus something for that pointer to point to.

Think of it this way:

         1          2
        +-----+    +------+
y------>|  x------>|  *x  |
        |  n  |    +------+
        +-----+

So you actually need the two allocations (1 and 2) to store everything.

Additionally, your type should be struct Vector *y since it's a pointer, and you should never cast the return value from malloc in C since it can hide certain problems you don't want hidden - C is perfectly capable of implicitly converting the void* return value to any other pointer.

And, of course, you probably want to encapsulate the creation of these vectors to make management of them easier, such as with:

struct Vector {
    double *data;    // no place for x and n in readable code :-)
    size_t size;
};

struct Vector *newVector (size_t sz) {
    // Try to allocate vector structure.

    struct Vector *retVal = malloc (sizeof (struct Vector));
    if (retVal == NULL)
        return NULL;

    // Try to allocate vector data, free structure if fail.

    retVal->data = malloc (sz * sizeof (double));
    if (retVal->data == NULL) {
        free (retVal);
        return NULL;
    }

    // Set size and return.

    retVal->size = sz;
    return retVal;
}

void delVector (struct Vector *vector) {
    // Can safely assume vector is NULL or fully built.

    if (vector != NULL) {
        free (vector->data);
        free (vector);
    }
}

By encapsulating the creation like that, you ensure that vectors are either fully built or not built at all - there's no chance of them being half-built. It also allows you to totally change the underlying data structures in future without affecting clients (for example, if you wanted to make them sparse arrays to trade off space for speed).

Others have posted some ways that you might be able to "coax" the Python interpreter into freeing the memory (or otherwise avoid having memory problems). Chances are you should try their ideas out first. However, I feel it important to give you a direct answer to your question.

There isn't really any way to directly tell Python to free memory. The fact of that matter is that if you want that low a level of control, you're going to have to write an extension in C or C++.

That said, there are some tools to help with this:

• cython
• swig
• boost python

I don't think you can do this with the standard tools. You can use ipcs -mp to get the process ID of the last process to attach/detach but I'm not aware of how to get all attached processes with ipcs.

With a two-process-attached segment, assuming they both stayed attached, you can possibly figure out from the creator PID cpid and last-attached PID lpid which are the two processes but that won't scale to more than two processes so its usefulness is limited.

The cat /proc/sysvipc/shm method seems similarly limited but I believe there's a way to do it with other parts of the /proc filesystem, as shown below:

When I do a grep on the procfs maps for all processes, I get entries containing lines for the cpid and lpid processes.

For example, I get the following shared memory segment from ipcs -m:

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status      
0x00000000 123456     pax        600        1024       2          dest

and, from ipcs -mp, the cpid is 3956 and the lpid is 9999 for that given shared memory segment (123456).

Then, with the command grep 123456 /proc/*/maps, I see:

/proc/3956/maps: blah blah blah 123456 /SYSV000000 (deleted)
/proc/9999/maps: blah blah blah 123456 /SYSV000000 (deleted)

So there is a way to get the processes that attached to it. I'm pretty certain that the dest status and (deleted) indicator are because the creator has marked the segment for destruction once the final detach occurs, not that it's already been destroyed.

So, by scanning of the /proc/*/maps "files", you should be able to discover which PIDs are currently attached to a given segment.

A logical address is a reference to memory location independent of the current assignment of data to memory. A physical address or absolute address is an actual location in main memory.

It is in chapter 7.2 of Stallings.

Yes. There is a simple way to remove everything in iPython. In iPython console, just type:

%reset

Then system will ask you to confirm. Press y. If you don't want to see this prompt, simply type:

%reset -f

This should work..

There is an interesting discussion here: http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/307d658a-f677-40f2-bdef-e6352b0bfe9e/ My understanding of this thread is that freeing small allocations are not reflected in Private Bytes or Working Set.

Long story short:

if I call

p=malloc(1000);
free(p);

then the Private Bytes reflect only the allocation, not the deallocation.

if I call

p=malloc(>512k);
free(p);

then the Private Bytes correctly reflect the allocation and the deallocation.

One of the reasons that C++ was designed was to make it easy to reuse code. In general, C++ should be written so that it works whether the class is instantiated on the heap, in an array, or on the stack. "Delete this" is a very bad coding practice because it will only work if a single instance is defined on the heap; and there had better not be another delete statement, which is typically used by most developers to clean up the heap. Doing this also assumes that no maintenance programmer in the future will cure a falsely perceived memory leak by adding a delete statement.

Even if you know in advance that your current plan is to only allocate a single instance on the heap, what if some happy-go-lucky developer comes along in the future and decides to create an instance on the stack? Or, what if he cuts and pastes certain portions of the class to a new class that he intends to use on the stack? When the code reaches "delete this" it will go off and delete it, but then when the object goes out of scope, it will call the destructor. The destructor will then try to delete it again and then you are hosed. In the past, doing something like this would screw up not only the program but the operating system and the computer would need to be rebooted. In any case, this is highly NOT recommended and should almost always be avoided. I would have to be desperate, seriously plastered, or really hate the company I worked for to write code that did this.

You may want to read this: "“Out Of Memory” Does Not Refer to Physical Memory" by Eric Lippert.

In short, and very simplified, "Out of memory" does not really mean that the amount of available memory is too small. The most common reason is that within the current address space, there is no contiguous portion of memory that is large enough to serve the wanted allocation. If you have 100 blocks, each 4 MB large, that is not going to help you when you need one 5 MB block.

Key Points:

• the data storage that we call “process memory” is in my opinion best visualized as a massive file on disk.
• RAM can be seen as merely a performance optimization
• Total amount of virtual memory your program consumes is really not hugely relevant to its performance
• "running out of RAM" seldom results in an “out of memory” error. Instead of an error, it results in bad performance because the full cost of the fact that storage is actually on disk suddenly becomes relevant.

First, define a new function to read the input (according to the structure of your input) and store the string, which means the memory in stack used. Set the length of string to be enough for your input.

Second, use strlen to measure the exact used length of string stored before, and malloc to allocate memory in heap, whose length is defined by strlen. The code is shown below.

int strLength = strlen(strInStack);
if (strLength == 0) {
    printf("\"strInStack\" is empty.\n");
}
else {
    char *strInHeap = (char *)malloc((strLength+1) * sizeof(char));
    strcpy(strInHeap, strInStack);
}
return strInHeap;

Finally, copy the value of strInStack to strInHeap using strcpy, and return the pointer to strInHeap. The strInStack will be freed automatically because it only exits in this sub-function.

I refer few writings.

reference:

• http://www.hanbit.co.kr/network/view.html?bi_id=1313
• How to get total RAM size of a device?

This getMemorySize() method is returned MemorySize that has total and free memory size.
I don't believe this code perfectly.
This code is testing on LG G3 cat.6 (v5.0.1)

    private MemorySize getMemorySize() {
        final Pattern PATTERN = Pattern.compile("([a-zA-Z]+):\\s*(\\d+)");

        MemorySize result = new MemorySize();
        String line;
        try {
            RandomAccessFile reader = new RandomAccessFile("/proc/meminfo", "r");
            while ((line = reader.readLine()) != null) {
                Matcher m = PATTERN.matcher(line);
                if (m.find()) {
                    String name = m.group(1);
                    String size = m.group(2);

                    if (name.equalsIgnoreCase("MemTotal")) {
                        result.total = Long.parseLong(size);
                    } else if (name.equalsIgnoreCase("MemFree") || name.equalsIgnoreCase("Buffers") ||
                            name.equalsIgnoreCase("Cached") || name.equalsIgnoreCase("SwapFree")) {
                        result.free += Long.parseLong(size);
                    }
                }
            }
            reader.close();

            result.total *= 1024;
            result.free *= 1024;
        } catch (IOException e) {
            e.printStackTrace();
        }

        return result;
    }

    private static class MemorySize {
        public long total = 0;
        public long free = 0;
    }

I know that Pattern.compile() is expensive cost so You may move its code to class member.

This is a nice trick to follow one or more programs in real time while also watching some other tool's output: watch "top -bn1 -p$(pidof foo),$(pidof bar); tool"

Note that memory usage on modern operating systems like Linux is an extremely complicated and difficult to understand area. In fact the chances of you actually correctly interpreting whatever numbers you get is extremely low. (Pretty much every time I look at memory usage numbers with other engineers, there is always a long discussion about what they actually mean that only results in a vague conclusion.)

Note: we now have much more extensive documentation on Managing Your App's Memory that covers much of the material here and is more up-to-date with the state of Android.

First thing is to probably read the last part of this article which has some discussion of how memory is managed on Android:

Service API changes starting with Android 2.0

Now ActivityManager.getMemoryInfo() is our highest-level API for looking at overall memory usage. This is mostly there to help an application gauge how close the system is coming to having no more memory for background processes, thus needing to start killing needed processes like services. For pure Java applications, this should be of little use, since the Java heap limit is there in part to avoid one app from being able to stress the system to this point.

Going lower-level, you can use the Debug API to get raw kernel-level information about memory usage: android.os.Debug.MemoryInfo

Note starting with 2.0 there is also an API, ActivityManager.getProcessMemoryInfo, to get this information about another process: ActivityManager.getProcessMemoryInfo(int[])

This returns a low-level MemoryInfo structure with all of this data:

    /** The proportional set size for dalvik. */
    public int dalvikPss;
    /** The private dirty pages used by dalvik. */
    public int dalvikPrivateDirty;
    /** The shared dirty pages used by dalvik. */
    public int dalvikSharedDirty;

    /** The proportional set size for the native heap. */
    public int nativePss;
    /** The private dirty pages used by the native heap. */
    public int nativePrivateDirty;
    /** The shared dirty pages used by the native heap. */
    public int nativeSharedDirty;

    /** The proportional set size for everything else. */
    public int otherPss;
    /** The private dirty pages used by everything else. */
    public int otherPrivateDirty;
    /** The shared dirty pages used by everything else. */
    public int otherSharedDirty;

But as to what the difference is between Pss, PrivateDirty, and SharedDirty... well now the fun begins.

A lot of memory in Android (and Linux systems in general) is actually shared across multiple processes. So how much memory a processes uses is really not clear. Add on top of that paging out to disk (let alone swap which we don't use on Android) and it is even less clear.

Thus if you were to take all of the physical RAM actually mapped in to each process, and add up all of the processes, you would probably end up with a number much greater than the actual total RAM.

The Pss number is a metric the kernel computes that takes into account memory sharing -- basically each page of RAM in a process is scaled by a ratio of the number of other processes also using that page. This way you can (in theory) add up the pss across all processes to see the total RAM they are using, and compare pss between processes to get a rough idea of their relative weight.

The other interesting metric here is PrivateDirty, which is basically the amount of RAM inside the process that can not be paged to disk (it is not backed by the same data on disk), and is not shared with any other processes. Another way to look at this is the RAM that will become available to the system when that process goes away (and probably quickly subsumed into caches and other uses of it).

That is pretty much the SDK APIs for this. However there is more you can do as a developer with your device.

Using adb, there is a lot of information you can get about the memory use of a running system. A common one is the command adb shell dumpsys meminfo which will spit out a bunch of information about the memory use of each Java process, containing the above info as well as a variety of other things. You can also tack on the name or pid of a single process to see, for example adb shell dumpsys meminfo system give me the system process:

** MEMINFO in pid 890 [system] **
                    native   dalvik    other    total
            size:    10940     7047      N/A    17987
       allocated:     8943     5516      N/A    14459
            free:      336     1531      N/A     1867
           (Pss):     4585     9282    11916    25783
  (shared dirty):     2184     3596      916     6696
    (priv dirty):     4504     5956     7456    17916

 Objects
           Views:      149        ViewRoots:        4
     AppContexts:       13       Activities:        0
          Assets:        4    AssetManagers:        4
   Local Binders:      141    Proxy Binders:      158
Death Recipients:       49
 OpenSSL Sockets:        0

 SQL
            heap:      205          dbFiles:        0
       numPagers:        0   inactivePageKB:        0
    activePageKB:        0

The top section is the main one, where size is the total size in address space of a particular heap, allocated is the kb of actual allocations that heap thinks it has, free is the remaining kb free the heap has for additional allocations, and pss and priv dirty are the same as discussed before specific to pages associated with each of the heaps.

If you just want to look at memory usage across all processes, you can use the command adb shell procrank. Output of this on the same system looks like:

  PID      Vss      Rss      Pss      Uss  cmdline
  890   84456K   48668K   25850K   21284K  system_server
 1231   50748K   39088K   17587K   13792K  com.android.launcher2
  947   34488K   28528K   10834K    9308K  com.android.wallpaper
  987   26964K   26956K    8751K    7308K  com.google.process.gapps
  954   24300K   24296K    6249K    4824K  com.android.phone
  948   23020K   23016K    5864K    4748K  com.android.inputmethod.latin
  888   25728K   25724K    5774K    3668K  zygote
  977   24100K   24096K    5667K    4340K  android.process.acore
...
   59     336K     332K      99K      92K  /system/bin/installd
   60     396K     392K      93K      84K  /system/bin/keystore
   51     280K     276K      74K      68K  /system/bin/servicemanager
   54     256K     252K      69K      64K  /system/bin/debuggerd

Here the Vss and Rss columns are basically noise (these are the straight-forward address space and RAM usage of a process, where if you add up the RAM usage across processes you get an ridiculously large number).

Pss is as we've seen before, and Uss is Priv Dirty.

Interesting thing to note here: Pss and Uss are slightly (or more than slightly) different than what we saw in meminfo. Why is that? Well procrank uses a different kernel mechanism to collect its data than meminfo does, and they give slightly different results. Why is that? Honestly I haven't a clue. I believe procrank may be the more accurate one... but really, this just leave the point: "take any memory info you get with a grain of salt; often a very large grain."

Finally there is the command adb shell cat /proc/meminfo that gives a summary of the overall memory usage of the system. There is a lot of data here, only the first few numbers worth discussing (and the remaining ones understood by few people, and my questions of those few people about them often resulting in conflicting explanations):

MemTotal:         395144 kB
MemFree:          184936 kB
Buffers:             880 kB
Cached:            84104 kB
SwapCached:            0 kB

MemTotal is the total amount of memory available to the kernel and user space (often less than the actual physical RAM of the device, since some of that RAM is needed for the radio, DMA buffers, etc).

MemFree is the amount of RAM that is not being used at all. The number you see here is very high; typically on an Android system this would be only a few MB, since we try to use available memory to keep processes running

Cached is the RAM being used for filesystem caches and other such things. Typical systems will need to have 20MB or so for this to avoid getting into bad paging states; the Android out of memory killer is tuned for a particular system to make sure that background processes are killed before the cached RAM is consumed too much by them to result in such paging.

You got some of these right, but whoever wrote the questions tricked you on at least one question:

• global variables -------> data (correct)
• static variables -------> data (correct)
• constant data types -----> code and/or data. Consider string literals for a situation when a constant itself would be stored in the data segment, and references to it would be embedded in the code
• local variables(declared and defined in functions) --------> stack (correct)
• variables declared and defined in main function -----> heap also stack (the teacher was trying to trick you)
• pointers(ex: char *arr, int *arr) -------> heap data or stack, depending on the context. C lets you declare a global or a static pointer, in which case the pointer itself would end up in the data segment.
• dynamically allocated space(using malloc, calloc, realloc) --------> stack heap

It is worth mentioning that "stack" is officially called "automatic storage class".

Updated Answer for Changed Documentation

The information is now spread across several guides in the documentation. Here's a list of required reading:

• Cocoa Core Competencies: Declared property
• Programming with Objective-C: Encapsulating Data
• Transitioning to ARC Release Notes
• Advanced Memory Management Programming Guide
• Objective-C Runtime Programming Guide: Declared Properties

The answer to this question now depends entirely on whether you're using an ARC-managed application (the modern default for new projects) or forcing manual memory management.

Assign vs. Weak - Use assign to set a property's pointer to the address of the object without retaining it or otherwise curating it; use weak to have the property point to nil automatically if the object assigned to it is deallocated. In most cases you'll want to use weak so you're not trying to access a deallocated object (illegal access of a memory address - "EXC_BAD_ACCESS") if you don't perform proper cleanup.

Retain vs. Copy - Declared properties use retain by default (so you can simply omit it altogether) and will manage the object's reference count automatically whether another object is assigned to the property or it's set to nil; Use copy to automatically send the newly-assigned object a -copy message (which will create a copy of the passed object and assign that copy to the property instead - useful (even required) in some situations where the assigned object might be modified after being set as a property of some other object (which would mean that modification/mutation would apply to the property as well).

It's really a matter of opinion. In your example, System.out.println(5) would be slightly more efficient, as you only refer to the number once and never change it. As was said in a comment, int is a primitive type and not a reference - thus it doesn't take up much space. However, you might want to set actual reference variables to null only if they are used in a very complicated method. All local reference variables are garbage collected when the method they are declared in returns.

You can catch it like any other exception:

try {
  foo();
}
catch (const std::bad_alloc&) {
  return -1;
}

Quite what you can usefully do from this point is up to you, but it's definitely feasible technically.

In general you cannot, and should not try, to respond to this error. bad_alloc indicates that a resource cannot be allocated because not enough memory is available. In most scenarios your program cannot hope to cope with that, and terminating soon is the only meaningful behaviour.

Worse, modern operating systems often over-allocate: on such systems, malloc and new can return a valid pointer even if there is not enough free memory left – std::bad_alloc will never be thrown, or is at least not a reliable sign of memory exhaustion. Instead, attempts to access the allocated memory will then result in a segmentation fault, which is not catchable (you can handle the segmentation fault signal, but you cannot resume the program afterwards).

The only thing you could do when catching std::bad_alloc is to perhaps log the error, and try to ensure a safe program termination by freeing outstanding resources (but this is done automatically in the normal course of stack unwinding after the error gets thrown if the program uses RAII appropriately).

In certain cases, the program may attempt to free some memory and try again, or use secondary memory (= disk) instead of RAM but these opportunities only exist in very specific scenarios with strict conditions:

1. The application must ensure that it runs on a system that does not overcommit memory, i.e. it signals failure upon allocation rather than later.
2. The application must be able to free memory immediately, without any further accidental allocations in the meantime.

It’s exceedingly rare that applications have control over point 1 — userspace applications never do, it’s a system-wide setting that requires root permissions to change.¹

OK, so let’s assume you’ve fixed point 1. What you can now do is for instance use a LRU cache for some of your data (probably some particularly large business objects that can be regenerated or reloaded on demand). Next, you need to put the actual logic that may fail into a function that supports retry — in other words, if it gets aborted, you can just relaunch it:

lru_cache<widget> widget_cache;

double perform_operation(int widget_id) {
    std::optional<widget> maybe_widget = widget_cache.find_by_id(widget_id);
    if (not maybe_widget) {
        maybe_widget = widget_cache.store(widget_id, load_widget_from_disk(widget_id));
    }
    return maybe_widget->frobnicate();
}

…

for (int num_attempts = 0; num_attempts < MAX_NUM_ATTEMPTS; ++num_attempts) {
    try {
        return perform_operation(widget_id);
    } catch (std::bad_alloc const&) {
        if (widget_cache.empty()) throw; // memory error elsewhere.
        widget_cache.remove_oldest();
    }
}

// Handle too many failed attempts here.

But even here, using std::set_new_handler instead of handling std::bad_alloc provides the same benefit and would be much simpler.

¹ If you’re creating an application that does control point 1, and you’re reading this answer, please shoot me an email, I’m genuinely curious about your circumstances.

What is the C++ Standard specified behavior of new in c++?

The usual notion is that if new operator cannot allocate dynamic memory of the requested size, then it should throw an exception of type std::bad_alloc.
However, something more happens even before a bad_alloc exception is thrown:

C++03 Section 3.7.4.1.3: says

An allocation function that fails to allocate storage can invoke the currently installed new_handler(18.4.2.2), if any. [Note: A program-supplied allocation function can obtain the address of the currently installed new_handler using the set_new_handler function (18.4.2.3).] If an allocation function declared with an empty exception-specification (15.4), throw(), fails to allocate storage, it shall return a null pointer. Any other allocation function that fails to allocate storage shall only indicate failure by throw-ing an exception of class std::bad_alloc (18.4.2.1) or a class derived from std::bad_alloc.

Consider the following code sample:

#include <iostream>
#include <cstdlib>

// function to call if operator new can't allocate enough memory or error arises
void outOfMemHandler()
{
    std::cerr << "Unable to satisfy request for memory\n";

    std::abort();
}

int main()
{
    //set the new_handler
    std::set_new_handler(outOfMemHandler);

    //Request huge memory size, that will cause ::operator new to fail
    int *pBigDataArray = new int[100000000L];

    return 0;
}

In the above example, operator new (most likely) will be unable to allocate space for 100,000,000 integers, and the function outOfMemHandler() will be called, and the program will abort after issuing an error message.

As seen here the default behavior of new operator when unable to fulfill a memory request, is to call the new-handler function repeatedly until it can find enough memory or there is no more new handlers. In the above example, unless we call std::abort(), outOfMemHandler() would be called repeatedly. Therefore, the handler should either ensure that the next allocation succeeds, or register another handler, or register no handler, or not return (i.e. terminate the program). If there is no new handler and the allocation fails, the operator will throw an exception.

What is the new_handler and set_new_handler?

new_handler is a typedef for a pointer to a function that takes and returns nothing, and set_new_handler is a function that takes and returns a new_handler.

Something like:

typedef void (*new_handler)();
new_handler set_new_handler(new_handler p) throw();

set_new_handler's parameter is a pointer to the function operator new should call if it can't allocate the requested memory. Its return value is a pointer to the previously registered handler function, or null if there was no previous handler.

How to handle out of memory conditions in C++?

Given the behavior of newa well designed user program should handle out of memory conditions by providing a proper new_handlerwhich does one of the following:

Make more memory available: This may allow the next memory allocation attempt inside operator new's loop to succeed. One way to implement this is to allocate a large block of memory at program start-up, then release it for use in the program the first time the new-handler is invoked.

Install a different new-handler: If the current new-handler can't make any more memory available, and of there is another new-handler that can, then the current new-handler can install the other new-handler in its place (by calling set_new_handler). The next time operator new calls the new-handler function, it will get the one most recently installed.

(A variation on this theme is for a new-handler to modify its own behavior, so the next time it's invoked, it does something different. One way to achieve this is to have the new-handler modify static, namespace-specific, or global data that affects the new-handler's behavior.)

Uninstall the new-handler: This is done by passing a null pointer to set_new_handler. With no new-handler installed, operator new will throw an exception ((convertible to) std::bad_alloc) when memory allocation is unsuccessful.

Throw an exception convertible to std::bad_alloc. Such exceptions are not be caught by operator new, but will propagate to the site originating the request for memory.

Not return: By calling abort or exit.

I would say that the consultant is right in the theory, and you are right in practice. As the saying goes:

In theory, theory and practice are the same. In practice, they are not.

The Java spec says that System.gc suggests to call garbage collection. In practice, it just spawns a thread and runs right away on the Sun JVM.

Although in theory you could be messing up some finely tuned JVM implementation of garbage collection, unless you are writing generic code intended to be deployed on any JVM out there, don't worry about it. If it works for you, do it.

Difference between STATIC MEMORY ALLOCATION & DYNAMIC MEMORY ALLOCATION

Memory is allocated before the execution of the program begins (During Compilation).
Memory is allocated during the execution of the program.

No memory allocation or deallocation actions are performed during Execution.
Memory Bindings are established and destroyed during the Execution.

Variables remain permanently allocated.
Allocated only when program unit is active.

Implemented using stacks and heaps.
Implemented using data segments.

Pointer is needed to accessing variables.
No need of Dynamically allocated pointers.

Faster execution than Dynamic.
Slower execution than static.

More memory Space required.
Less Memory space required.

If you want to grow the array dynamically, you should use malloc() to dynamically allocate some fixed amount of memory, and then use realloc() whenever you run out. A common technique is to use an exponential growth function such that you allocate some small fixed amount and then make the array grow by duplicating the allocated amount.

Some example code would be:

size = 64; i = 0;
x = malloc(sizeof(words)*size); /* enough space for 64 words */
while (read_words()) {
    if (++i > size) {
        size *= 2;
        x = realloc(sizeof(words) * size);
    }
}
/* done with x */
free(x);

It is safe unless you overloaded the delete operator. if you overloaded the delete operator and not handling null condition then it is not safe at all.

When I asked this question, my real question was, "is there a difference between the two? Doesn't the runtime have to keep information about the array size, and so will it not be able to tell which one we mean?" This question does not appear in "related questions", so just to help out those like me, here is the answer to that: "why do we even need the delete[] operator?"

Also, don't use manually allocated memory if there's a std library class (e.g. vector). Make sure if you violate that rule that you have a virtual destructor.

Memory allocated on the heap can be subject to high-water marks. This is complicated by Python's internal optimizations for allocating small objects (PyObject_Malloc) in 4 KiB pools, classed for allocation sizes at multiples of 8 bytes -- up to 256 bytes (512 bytes in 3.3). The pools themselves are in 256 KiB arenas, so if just one block in one pool is used, the entire 256 KiB arena will not be released. In Python 3.3 the small object allocator was switched to using anonymous memory maps instead of the heap, so it should perform better at releasing memory.

Additionally, the built-in types maintain freelists of previously allocated objects that may or may not use the small object allocator. The int type maintains a freelist with its own allocated memory, and clearing it requires calling PyInt_ClearFreeList(). This can be called indirectly by doing a full gc.collect.

Try it like this, and tell me what you get. Here's the link for psutil.Process.memory_info.

import os
import gc
import psutil

proc = psutil.Process(os.getpid())
gc.collect()
mem0 = proc.get_memory_info().rss

# create approx. 10**7 int objects and pointers
foo = ['abc' for x in range(10**7)]
mem1 = proc.get_memory_info().rss

# unreference, including x == 9999999
del foo, x
mem2 = proc.get_memory_info().rss

# collect() calls PyInt_ClearFreeList()
# or use ctypes: pythonapi.PyInt_ClearFreeList()
gc.collect()
mem3 = proc.get_memory_info().rss

pd = lambda x2, x1: 100.0 * (x2 - x1) / mem0
print "Allocation: %0.2f%%" % pd(mem1, mem0)
print "Unreference: %0.2f%%" % pd(mem2, mem1)
print "Collect: %0.2f%%" % pd(mem3, mem2)
print "Overall: %0.2f%%" % pd(mem3, mem0)

Output:

Allocation: 3034.36%
Unreference: -752.39%
Collect: -2279.74%
Overall: 2.23%

Edit:

I switched to measuring relative to the process VM size to eliminate the effects of other processes in the system.

The C runtime (e.g. glibc, msvcrt) shrinks the heap when contiguous free space at the top reaches a constant, dynamic, or configurable threshold. With glibc you can tune this with mallopt (M_TRIM_THRESHOLD). Given this, it isn't surprising if the heap shrinks by more -- even a lot more -- than the block that you free.

In 3.x range doesn't create a list, so the test above won't create 10 million int objects. Even if it did, the int type in 3.x is basically a 2.x long, which doesn't implement a freelist.

Does it have to be done in Java? I.e. does it need to be platform independent? If not, I'd suggest using the 'split' command in *nix. If you really wanted, you could execute this command via your java program. While I haven't tested, I imagine it perform faster than whatever Java IO implementation you could come up with.

If there are constraints that, you cannot waste a single byte, then this solution works: Note: There is a case where this may be executed infinitely :D

   void *mem;  
   void *ptr;
try:
   mem =  malloc(1024);  
   if (mem % 16 != 0) {  
       free(mem);  
       goto try;
   }  
   ptr = mem;  
   memset_16aligned(ptr, 0, 1024);

On Cygwin -mcmodel=medium is already default and doesn't help. To me adding -Wl,--image-base -Wl,0x10000000 to GCC linker did fixed the error.

After one of my fixes for managed application I had the same thing, like how to verify that my application will not have the same memory leak after my next change, so I've wrote something like Object Release Verification framework, please take a look on the NuGet package ObjectReleaseVerification. You can find a sample here https://github.com/outcoldman/OutcoldSolutions-ObjectReleaseVerification-Sample, and information about this sample http://outcoldman.ru/en/blog/show/322

Below is my function decorator which allows to track how much memory this process consumed before the function call, how much memory it uses after the function call, and how long the function is executed.

import time
import os
import psutil


def elapsed_since(start):
    return time.strftime("%H:%M:%S", time.gmtime(time.time() - start))


def get_process_memory():
    process = psutil.Process(os.getpid())
    return process.memory_info().rss


def track(func):
    def wrapper(*args, **kwargs):
        mem_before = get_process_memory()
        start = time.time()
        result = func(*args, **kwargs)
        elapsed_time = elapsed_since(start)
        mem_after = get_process_memory()
        print("{}: memory before: {:,}, after: {:,}, consumed: {:,}; exec time: {}".format(
            func.__name__,
            mem_before, mem_after, mem_after - mem_before,
            elapsed_time))
        return result
    return wrapper

So, when you have some function decorated with it

from utils import track

@track
def list_create(n):
    print("inside list create")
    return [1] * n

You will be able to see this output:

inside list create
list_create: memory before: 45,928,448, after: 46,211,072, consumed: 282,624; exec time: 00:00:00

Working with the many answers above, I have implemented Apples new method os_proc_available_memory() for iOS 13+ coupled with NSByteCountFormatter which offers a number of useful formatting options for nicer output of the memory:

#include <os/proc.h>

....

- (NSString *)memoryStringForBytes:(unsigned long long)memoryBytes {
    NSByteCountFormatter *byteFormatter = [[NSByteCountFormatter alloc] init];
    byteFormatter.allowedUnits = NSByteCountFormatterUseGB;
    byteFormatter.countStyle = NSByteCountFormatterCountStyleMemory;
    NSString *memoryString = [byteFormatter stringFromByteCount:memoryBytes];
    return memoryString;
}

- (void)memoryLoggingOutput {
    if (@available(iOS 13.0, *)) {
        NSLog(@"Physical memory available: %@", [self memoryStringForBytes:[NSProcessInfo processInfo].physicalMemory]);
        NSLog(@"Memory A (brackets): %@", [self memoryStringForBytes:(long)os_proc_available_memory()]);
        NSLog(@"Memory B (no brackets): %@", [self memoryStringForBytes:(long)os_proc_available_memory]);
    }
}

Important note: Do not forget the () at the end. I have included both NSLog options in in the memoryLoggingOutput method because it does not warn you that they are missing and failure to include the brackets returns an unexpected yet constant result.

The string returned from the method memoryStringForBytes outputs values like so:

NSLog(@"%@", [self memoryStringForBytes:(long)os_proc_available_memory()]); // 1.93 GB
// 2 seconds later
NSLog(@"%@", [self memoryStringForBytes:(long)os_proc_available_memory()]); // 1.84 GB

Something throws an exception of type std::bad_alloc, indicating that you ran out of memory. This exception is propagated through until main, where it "falls off" your program and causes the error message you see.

Since nobody here knows what "RectInvoice", "rectInvoiceVector", "vect", "im" and so on are, we cannot tell you what exactly causes the out-of-memory condition. You didn't even post your real code, because w h looks like a syntax error.

Maybe Iterator’s remove() method? The JDK’s default collection classes should all creator iterators that support this method.

if it crashes on the delete line then you have almost certainly somehow corrupted the heap. We would need to see more code to diagnose the problem since the example you presented has no errors.

Perhaps you have a buffer overflow on the heap which corrupted the heap structures or even something as simple as a "double free" (or in the c++ case "double delete").

Also, as The Fuzz noted, you may have an error in your destructor as well.

And yes, it is completely normal and expected for delete to invoke the destructor, that is in fact one of its two purposes (call destructor then free memory).

You should delete A yourself in the destructor of B.

It is useful if you are building a kernel - where do you place the kernel code you read from disk or the pagetable? You need to know where to jump to.

Or in other, very rare circumstances such as when you have loads of allocated room and want to place a few structures behind each other. They can be packed this way without the need for the offsetof() operator. There are other tricks for that too, though.

I also believe some STL implementations make use of placement new, like std::vector. They allocate room for 2^n elements that way and don't need to always realloc.

Before you know about the attributes of @property, you should know what is the use of @property.

• @property offers a way to define the information that a class is intended to encapsulate. If you declare an object/variable using @property, then that object/variable will be accessible to other classes importing its class.

• If you declare an object using @property in the header file, then you have to synthesize it using @synthesize in the implementation file. This makes the object KVC compliant. By default, compiler will synthesize accessor methods for this object.

• accessor methods are : setter and getter.

Example: .h

@interface XYZClass : NSObject
@property (nonatomic, retain) NSString *name;
@end

.m

@implementation XYZClass
@synthesize name;
@end

Now the compiler will synthesize accessor methods for name.

XYZClass *obj=[[XYZClass alloc]init];
NSString *name1=[obj name]; // get 'name'
[obj setName:@"liza"]; // first letter of 'name' becomes capital in setter method

• List of attributes of @property

  atomic, nonatomic, retain, copy, readonly, readwrite, assign, strong, getter=method, setter=method, unsafe_unretained

• atomic is the default behavior. If an object is declared as atomic then it becomes thread-safe. Thread-safe means, at a time only one thread of a particular instance of that class can have the control over that object.

If the thread is performing getter method then other thread cannot perform setter method on that object. It is slow.

@property NSString *name; //by default atomic`
@property (atomic)NSString *name; // explicitly declared atomic`

• nonatomic is not thread-safe. You can use the nonatomic property attribute to specify that synthesized accessors simply set or return a value directly, with no guarantees about what happens if that same value is accessed simultaneously from different threads.

For this reason, it’s faster to access a nonatomic property than an atomic one.

@property (nonatomic)NSString *name;   

• retain is required when the attribute is a pointer to an object.

The setter method will increase retain count of the object, so that it will occupy memory in autorelease pool.

@property (retain)NSString *name;

• copy If you use copy, you can't use retain. Using copy instance of the class will contain its own copy.

Even if a mutable string is set and subsequently changed, the instance captures whatever value it has at the time it is set. No setter and getter methods will be synthesized.

@property (copy) NSString *name;

now,

NSMutableString *nameString = [NSMutableString stringWithString:@"Liza"];    
xyzObj.name = nameString;    
[nameString appendString:@"Pizza"]; 

name will remain unaffected.

• readonly If you don't want to allow the property to be changed via setter method, you can declare the property readonly.

Compiler will generate a getter, but not a setter.

@property (readonly) NSString *name;

• readwrite is the default behavior. You don't need to specify readwrite attribute explicitly.

It is opposite of readonly.

@property (readwrite) NSString *name;

• assign will generate a setter which assigns the value to the instance variable directly, rather than copying or retaining it. This is best for primitive types like NSInteger and CGFloat, or objects you don't directly own, such as delegates.

Keep in mind retain and assign are basically interchangeable when garbage collection is enabled.

@property (assign) NSInteger year;

• strong is a replacement for retain.

It comes with ARC.

@property (nonatomic, strong) AVPlayer *player; 

• getter=method If you want to use a different name for a getter method, it’s possible to specify a custom name by adding attributes to the property.

In the case of Boolean properties (properties that have a YES or NO value), it’s customary for the getter method to start with the word “is”

@property (getter=isFinished) BOOL finished;

• setter=method If you want to use a different name for a setter method, it’s possible to specify a custom name by adding attributes to the property.

The method should end with a colon.

@property(setter = boolBool:) BOOL finished;

• unsafe_unretained There are a few classes in Cocoa and Cocoa Touch that don’t yet support weak references, which means you can’t declare a weak property or weak local variable to keep track of them. These classes include NSTextView, NSFont and NSColorSpace,etc. If you need to use a weak reference to one of these classes, you must use an unsafe reference.

An unsafe reference is similar to a weak reference in that it doesn’t keep its related object alive, but it won’t be set to nil if the destination object is deallocated.

@property (unsafe_unretained) NSObject *unsafeProperty;

If you need to specify multiple attributes, simply include them as a comma-separated list, like this:

@property (readonly, getter=isFinished) BOOL finished;

Use malloc and free only for allocating memory that is going to be managed by c-centric libraries and APIs. Use new and delete (and the [] variants) for everything that you control.

.so files are dynamic libraries. The suffix stands for "shared object", because all the applications that are linked with the library use the same file, rather than making a copy in the resulting executable.

.a files are static libraries. The suffix stands for "archive", because they're actually just an archive (made with the ar command -- a predecessor of tar that's now just used for making libraries) of the original .o object files.

.la files are text files used by the GNU "libtools" package to describe the files that make up the corresponding library. You can find more information about them in this question: What are libtool's .la file for?

Static and dynamic libraries each have pros and cons.

Static pro: The user always uses the version of the library that you've tested with your application, so there shouldn't be any surprising compatibility problems.

Static con: If a problem is fixed in a library, you need to redistribute your application to take advantage of it. However, unless it's a library that users are likely to update on their own, you'd might need to do this anyway.

Dynamic pro: Your process's memory footprint is smaller, because the memory used for the library is amortized among all the processes using the library.

Dynamic pro: Libraries can be loaded on demand at run time; this is good for plugins, so you don't have to choose the plugins to be used when compiling and installing the software. New plugins can be added on the fly.

Dynamic con: The library might not exist on the system where someone is trying to install the application, or they might have a version that's not compatible with the application. To mitigate this, the application package might need to include a copy of the library, so it can install it if necessary. This is also often mitigated by package managers, which can download and install any necessary dependencies.

Dynamic con: Link-Time Optimization is generally not possible, so there could possibly be efficiency implications in high-performance applications. See the Wikipedia discussion of WPO and LTO.

Dynamic libraries are especially useful for system libraries, like libc. These libraries often need to include code that's dependent on the specific OS and version, because kernel interfaces have changed. If you link a program with a static system library, it will only run on the version of the OS that this library version was written for. But if you use a dynamic library, it will automatically pick up the library that's installed on the system you run on.

The problem may be due to mixed build platforms DLLs in the project. i.e You build your project to Any CPU but have some DLLs in the project already built for x86 platform. These will cause random crashes because of different memory mapping of 32bit and 64bit architecture. If all the DLLs are built for one platform the problem can be solved.

I've had a lot of problems trying to get Eclipse to accept as much memory as I'd like it to be able to use (between 2 and 4 gigs for example).

Open eclipse.ini in the Eclipse installation directory. You should be able to change the memory sizes after -vmargs up to 1024 without a problem up to some maximum value that's dependent on your system. Here's that section on my Linux box:

-vmargs
-Dosgi.requiredJavaVersion=1.5
-XX:MaxPermSize=512m
-Xms512m
-Xmx1024m

And here's that section on my Windows box:

-vmargs
-Xms256m
-Xmx1024m

But, I've failed at setting it higher than 1024 megs. If anybody knows how to make that work, I'd love to know.

EDIT: 32bit version of juno seems to not accept more than Xmx1024m where the 64 bit version accept 2048.

EDIT: Nick's post contains some great links that explain two different things:

• The problem is largely dependent on your system and the amount of contiguous free memory available, and
• By using javaw.exe (on Windows), you may be able to get a larger allocated block of memory.

I have 8 gigs of Ram and can't set -Xmx to more than 1024 megs of ram, even when a minimal amount of programs are loaded and both windows/linux report between 4 and 5 gigs of free ram.

Tracemalloc module was integrated as a built-in module starting from Python 3.4, and appearently, it's also available for prior versions of Python as a third-party library (haven't tested it though).

This module is able to output the precise files and lines that allocated the most memory. IMHO, this information is infinitly more valuable than the number of allocated instances for each type (which ends up being a lot of tuples 99% of the time, which is a clue, but barely helps in most cases).

I recommend you use tracemalloc in combination with pyrasite. 9 times out of 10, running the top 10 snippet in a pyrasite-shell will give you enough information and hints to to fix the leak within 10 minutes. Yet, if you're still unable to find the leak cause, pyrasite-shell in combination with the other tools mentioned in this thread will probably give you some more hints too. You should also take a look on all the extra helpers provided by pyrasite (such as the memory viewer).

As jzd says, you can use System.currentTimeMillis. If you need it in a Date object but don't want to create a new Date object, you can use Date.setTime to reuse an existing Date object. Personally I hate the fact that Date is mutable, but maybe it's useful to you in this particular case. Similarly, Calendar has a setTimeInMillis method.

If possible though, it would probably be better just to keep it as a long. If you only need a timestamp, effectively, then that would be the best approach.

To answer this question it's critical whether the Java VM is in CLIENT or SERVER mode. You can specify "-client" or "-server" options. Otherwise java uses internal rules; basically win32 is always client and Linux is always server, but see the table here:

http://docs.oracle.com/javase/6/docs/technotes/guides/vm/server-class.html

Sun/Oracle jre6u18 doc says re client: the VM gets 1/2 of physical memory if machine has <= 192MB; 1/4 of memory if machine has <= 1Gb; max 256Mb. In my test on a 32bit WindowsXP system with 2Gb phys mem, Java allocated 256Mb, which agrees with the doc.

Sun/Oracle jre6u18 doc says re server: same as client, then adds confusing language: for 32bit JVM the default max is 1Gb, and for 64 bit JVM the default is 32Gb. In my test on a 64bit linux machine with 8Gb physical, Java allocates 2Gb, which is 1/4 of physical; on a 64bit linux machine with 128Gb physical Java allocates 32Gb, again 1/4 of physical.

Thanks to this SO post for guiding me:

Definition of server-class machine changed recently?

I found on on Windows 7/8 (64-bit), as of Android Studio 1.1.0:

[INSTALL_DIR]\bin\studio64.exe.vmoptions be used (if it exists), otherwise it would always fall back to %USERPROFILE%.\AndroidStudio\studio[64].exe.vmoptions

If you want the settings managed from %USERPROFILE%.\AndroidStudio\studio[64].exe.vmoptions, just delete the one in the installation directory.

Error

ORA-04031: unable to allocate 4064 bytes of shared memory ("shared pool","select increment$,minvalue,m...","sga heap(3,0)","kglsim heap")

Solution: by nepasoft nepal

• 1.-

  ps -ef|grep oracle
  

• 2.- Find the smon and kill the pid for it

• 3.-

  SQL> startup mount
  ORACLE instance started.
  
  Total System Global Area 4831838208 bytes
  Fixed Size                  2027320 bytes
  Variable Size            4764729544 bytes
  Database Buffers           50331648 bytes
  Redo Buffers               14749696 bytes
  Database mounted.
  

• 4.-

  SQL> alter system set shared_pool_size=100M scope=spfile;
  
  System altered.
  

• 5.-

  SQL> shutdown immediate
  
  ORA-01109: database not open
  Database dismounted.
  ORACLE instance shut down.
  

• 6.-

  SQL> startup
  ORACLE instance started.
  
  Total System Global Area 4831838208 bytes
  Fixed Size                  2027320 bytes
  Variable Size            4764729544 bytes
  Database Buffers           50331648 bytes
  Redo Buffers               14749696 bytes
  Database mounted.
  Database opened.
  

• 7.-

  SQL> create pfile from spfile;
  
  File created.
  

SOLVED

new allocates objects on the heap. Otherwise, objects are allocated on the stack. Look up the difference between the two.

Old:

maxrss states the maximum available memory for the process. 0 means that no limit is put upon the process. What you probably want is unshared data usage ru_idrss.

New: It seems that the above does not actually work, as the kernel does not fill most of the values. What does work is to get the information from proc. Instead of parsing it oneself though, it is easier to use libproc (part of procps) as follows:

// getrusage.c
#include <stdio.h>
#include <proc/readproc.h>

int main() {
  struct proc_t usage;
  look_up_our_self(&usage);
  printf("usage: %lu\n", usage.vsize);
}

Compile with "gcc -o getrusage getrusage.c -lproc"

also,

the global new and delete can be overridden, malloc/free cannot.

further more new and delete can be overridden per type.

Check that the application on the test device and Google Play developer console really match.

I might have a bit of a special case but it might help someone: First, I had uploaded a package to Google Play that I had created with an ant build script. Second, on the test device, I debugged the same application (or so I thought). I got the "Error while retrieving information from server. [RPC:S-7:AEC-0]", and logcat displayed:

Class not found when unmarshalling: com.google.android.finsky.billing.lightpurchase.PurchaseParams, e: java.lang.ClassNotFoundException: com.google.android.finsky.billing.lightpurchase.PurchaseParams

The problem was that in the ant script, I have aapt command for modifying the package name. However, Eclipse does not run that command, so there was a package name mismatch between the applications in Google Play and the test device.

in the settings.py of your project, check line 28, where is the Allows Host

settings.py

ALLOWED_HOSTS = ['IP', 'servidor', ]

you must put the IP and the server you use, level local or web settings.py

ALLOWED_HOSTS = ['127.0.0.1', 'localhost', 'www.ejemplo.com']

or

ALLOWED_HOSTS = ['*']

To zoom relative to the mouse position, all you need is:

var position = e.GetPosition(image1);
image1.RenderTransformOrigin = new Point(position.X / image1.ActualWidth, position.Y / image1.ActualHeight);

A developer recently added subtitle support to VideoView.

When the MediaPlayer starts playing a music (or other source), it checks if there is a SubtitleController and shows this message if it's not set. It doesn't seem to care about if the source you want to play is a music or video. Not sure why he did that.

Short answer: Don't care about this "Exception".

Edit :

Still present in Lollipop,

If MediaPlayer is only used to play audio files and you really want to remove these errors in the logcat, the code bellow set an empty SubtitleController to the MediaPlayer.

It should not be used in production environment and may have some side effects.

static MediaPlayer getMediaPlayer(Context context){

    MediaPlayer mediaplayer = new MediaPlayer();

    if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.KITKAT) {
        return mediaplayer;
    }

    try {
        Class<?> cMediaTimeProvider = Class.forName( "android.media.MediaTimeProvider" );
        Class<?> cSubtitleController = Class.forName( "android.media.SubtitleController" );
        Class<?> iSubtitleControllerAnchor = Class.forName( "android.media.SubtitleController$Anchor" );
        Class<?> iSubtitleControllerListener = Class.forName( "android.media.SubtitleController$Listener" );

        Constructor constructor = cSubtitleController.getConstructor(new Class[]{Context.class, cMediaTimeProvider, iSubtitleControllerListener});

        Object subtitleInstance = constructor.newInstance(context, null, null);

        Field f = cSubtitleController.getDeclaredField("mHandler");

        f.setAccessible(true);
        try {
            f.set(subtitleInstance, new Handler());
        }
        catch (IllegalAccessException e) {return mediaplayer;}
        finally {
            f.setAccessible(false);
        }

        Method setsubtitleanchor = mediaplayer.getClass().getMethod("setSubtitleAnchor", cSubtitleController, iSubtitleControllerAnchor);

        setsubtitleanchor.invoke(mediaplayer, subtitleInstance, null);
        //Log.e("", "subtitle is setted :p");
    } catch (Exception e) {}

    return mediaplayer;
}

This code is trying to do the following from the hidden API

SubtitleController sc = new SubtitleController(context, null, null);
sc.mHandler = new Handler();
mediaplayer.setSubtitleAnchor(sc, null)

The universal solution is to connect your device to Mac and to observe what's going on during installation. I got an error:

Could not load download manifest with underlying error: Error Domain=NSURLErrorDomain Code=-1202 "Cannot connect to the Store" UserInfo=0x146635d0 {NSLocalizedDescription=Cannot connect to the Store, NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, NSLocalizedFailureReason=A secure connection could not be established. Please check your Date & Time settings., NSErrorFailingURLStringKey=https://myserver.com/app/manifest.plist, NSUnderlyingError=0x14678880 "The certificate for this server is invalid. You might be connecting to a server that is pretending to be “myserver.com” which could put your confidential information at risk.", NSURLErrorFailingURLPeerTrustErrorKey=, NSErrorFailingURLKey=https://myserver.com/app/manifest.plist}

There was even the suggestion in that error to check date settings. For some reason the date was 1 January 1970. Setting correct date solved the problem.

For a quick and lazy solution, (and not using VS at all) try these online converters:

• xsd-to-xml-converter here
• xmltocsharp converter here

XSD => XML => C# classes

Example XSD:

<?xml version="1.0" encoding="UTF-8" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="shiporder">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="orderperson" type="xs:string"/>
      <xs:element name="shipto">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="name" type="xs:string"/>
            <xs:element name="address" type="xs:string"/>
            <xs:element name="city" type="xs:string"/>
            <xs:element name="country" type="xs:string"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
      <xs:element name="item" maxOccurs="unbounded">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="title" type="xs:string"/>
            <xs:element name="note" type="xs:string" minOccurs="0"/>
            <xs:element name="quantity" type="xs:positiveInteger"/>
            <xs:element name="price" type="xs:decimal"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
    <xs:attribute name="orderid" type="xs:string" use="required"/>
  </xs:complexType>
</xs:element>

</xs:schema>

Converts to XML:

<?xml version="1.0" encoding="utf-8"?>
<!-- Created with Liquid Technologies Online Tools 1.0 (https://www.liquid-technologies.com) -->
<shiporder xsi:noNamespaceSchemaLocation="schema.xsd" orderid="string" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <orderperson>string</orderperson>
  <shipto>
    <name>string</name>
    <address>string</address>
    <city>string</city>
    <country>string</country>
  </shipto>
  <item>
    <title>string</title>
    <note>string</note>
    <quantity>3229484693</quantity>
    <price>-6894.465094196054907</price>
  </item>
  <item>
    <title>string</title>
    <note>string</note>
    <quantity>2181272155</quantity>
    <price>-2645.585094196054907</price>
  </item>
  <item>
    <title>string</title>
    <note>string</note>
    <quantity>2485046602</quantity>
    <price>4023.034905803945093</price>
  </item>
  <item>
    <title>string</title>
    <note>string</note>
    <quantity>1342091380</quantity>
    <price>-810.825094196054907</price>
  </item>
</shiporder>

Which converts to this class structure:

   /* 
    Licensed under the Apache License, Version 2.0

    http://www.apache.org/licenses/LICENSE-2.0
    */
using System;
using System.Xml.Serialization;
using System.Collections.Generic;
namespace Xml2CSharp
{
    [XmlRoot(ElementName="shipto")]
    public class Shipto {
        [XmlElement(ElementName="name")]
        public string Name { get; set; }
        [XmlElement(ElementName="address")]
        public string Address { get; set; }
        [XmlElement(ElementName="city")]
        public string City { get; set; }
        [XmlElement(ElementName="country")]
        public string Country { get; set; }
    }

    [XmlRoot(ElementName="item")]
    public class Item {
        [XmlElement(ElementName="title")]
        public string Title { get; set; }
        [XmlElement(ElementName="note")]
        public string Note { get; set; }
        [XmlElement(ElementName="quantity")]
        public string Quantity { get; set; }
        [XmlElement(ElementName="price")]
        public string Price { get; set; }
    }

    [XmlRoot(ElementName="shiporder")]
    public class Shiporder {
        [XmlElement(ElementName="orderperson")]
        public string Orderperson { get; set; }
        [XmlElement(ElementName="shipto")]
        public Shipto Shipto { get; set; }
        [XmlElement(ElementName="item")]
        public List<Item> Item { get; set; }
        [XmlAttribute(AttributeName="noNamespaceSchemaLocation", Namespace="http://www.w3.org/2001/XMLSchema-instance")]
        public string NoNamespaceSchemaLocation { get; set; }
        [XmlAttribute(AttributeName="orderid")]
        public string Orderid { get; set; }
        [XmlAttribute(AttributeName="xsi", Namespace="http://www.w3.org/2000/xmlns/")]
        public string Xsi { get; set; }
    }

}

Attention! Take in account that this is just to Get-You-Started, the results obviously need refinements!

Found this as I was searching for which way is fastest to pull the second element of a 2-tuple list. Not what I wanted but ran same test as shown with a 3rd method plus test the zip method

setup = 'elements = [(1,1) for _ in range(100000)];from operator import itemgetter'
method1 = '[x[1] for x in elements]'
method2 = 'map(itemgetter(1), elements)'
method3 = 'dict(elements).values()'
method4 = 'zip(*elements)[1]'

import timeit
t = timeit.Timer(method1, setup)
print('Method 1: ' + str(t.timeit(100)))
t = timeit.Timer(method2, setup)
print('Method 2: ' + str(t.timeit(100)))
t = timeit.Timer(method3, setup)
print('Method 3: ' + str(t.timeit(100)))
t = timeit.Timer(method4, setup)
print('Method 4: ' + str(t.timeit(100)))

Method 1: 0.618785858154
Method 2: 0.711684942245
Method 3: 0.298138141632
Method 4: 1.32586884499

So over twice as fast if you have a 2 tuple pair to just convert to a dict and take the values.

Depending on the language you're using it's going to be something simple like

CInt(CDate("1970-1-1") - CDate(Today()))

Ironically enough, yesterday was day 40,000 if you use 1/1/1900 as "day zero" like many computer systems use.

Just use it like it was an object you defined. i.e.

$trends = $json_output->trends;

I don't see any margin or margin-left declarations for #footer-wrap li.

This ought to do the trick:

#footer-wrap ul,
#footer-wrap li {
    margin-left: 0;
    list-style-type: none;
}

In Laravel 5 I had to ssh into my homestead server and run these commands:

sudo chmod -R 777 storage
sudo chmod -R 777 bootstrap/cache

Without a for loop, only using Map().

You can also return the duplicates.

(function(a){
  let map = new Map();

  a.forEach(e => {
    if(map.has(e)) {
      let count = map.get(e);
      console.log(count)
      map.set(e, count + 1);
    } else {
      map.set(e, 1);
    }
  });

  let hasDup = false;
  let dups = [];
  map.forEach((value, key) => {
    if(value > 1) {
      hasDup = true;
      dups.push(key);
    }
  });
   console.log(dups);
   return hasDup;
 })([2,4,6,2,1,4]);

For me, it said Module did not found and not worked. Finally, I found this solution and worked.

<img v-bind:src="require('@' + baseUrl + 'path/path' + obj.key +'.png')"/>

Needed to add '@' at the beginning of the local path.

This is possible if the browser supports the download property in anchor elements.

var sampleBytes = new Int8Array(4096);

var saveByteArray = (function () {
    var a = document.createElement("a");
    document.body.appendChild(a);
    a.style = "display: none";
    return function (data, name) {
        var blob = new Blob(data, {type: "octet/stream"}),
            url = window.URL.createObjectURL(blob);
        a.href = url;
        a.download = name;
        a.click();
        window.URL.revokeObjectURL(url);
    };
}());

saveByteArray([sampleBytes], 'example.txt');

JSFiddle: http://jsfiddle.net/VB59f/2

Here you go!

Mozilla/5.0 (iPad; U; CPU OS 3_2 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Version/4.0.4 Mobile/7B334b Safari/531.21.10

I made a fiddle that uses FlexBox and will also give you different styles of HR (double line, symbols in the center of the line, drop shadow, inset, dashed, etc).

CSS

button {
    padding: 8px;
    border-radius: 4px;
    background-color: #fff;
    border: 1px solid #ccc;
    margin: 2px;
  }

  button:hover {
    cursor: pointer;
  }

  button.active {
    background-color: rgb(34, 179, 247);
    color: #fff;
  }

  .codeBlock {
    display: none;
  }

  .htmlCode, .cssCode {
    background-color: rgba(34, 179, 247, 0.5); 
    width: 100%;
    padding: 10px;
  }

  .divider {
    display: flex;
    flex-direction: row;
    flex-flow: row;
    width: 100%;
  }

  .divider.fixed {
    width: 400px;
  }

  .divider > label {
    align-self: baseline;
    flex-grow: 2;
    white-space: nowrap;
  }

  .divider > hr {
    margin-top: 10px;
    width: 100%;
    border: 0;
    height: 1px;
    background: #666;
  }

  .divider.left > label {
    order: 1;
    padding-right: 5px;
  }

  .divider.left > hr {
    order: 2
  }

  .divider.right > label {
    padding-left: 5px;
  }
  /* hr bars with centered text */
  /* first HR in a centered version */

  .divider.center >:first-child {
    margin-right: 5px;
  }
  /* second HR in a centered version */

  .divider.center >:last-child {
    margin-left: 5px;
  }
  /** HR style variations **/

  hr.gradient {
    background: transparent;
    background-image: linear-gradient(to right, #f00, #333, #f00);
  }

  hr.gradient2 {
    background: transparent;
    background-image: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(255, 0, 0, 0.5), rgba(0, 0, 0, 0));
  }

  hr.dashed {
    background: transparent;
    border: 0;
    border-top: 1px dashed #666;
  }

  hr.dropshadow {
    background: transparent;
    height: 12px;
    border: 0;
    box-shadow: inset 0 12px 12px -12px rgba(0, 0, 0, 0.5);
  }

  hr.blur {
    background: transparent;
    border: 0;
    height: 0;
    /* Firefox... */
    box-shadow: 0 0 10px 1px black;
  }

  hr.blur:after {
    background: transparent;
    /* Not really supposed to work, but does */
    content: "\00a0";
    /* Prevent margin collapse */
  }

  hr.inset {
    background: transparent;
    border: 0;
    height: 0;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
  }

  hr.flared {
    background: transparent;
    overflow: visible;
    /* For IE */
    height: 30px;
    border-style: solid;
    border-color: black;
    border-width: 1px 0 0 0;
    border-radius: 20px;
  }

  hr.flared:before {
    background: transparent;
    display: block;
    content: "";
    height: 30px;
    margin-top: -31px;
    border-style: solid;
    border-color: black;
    border-width: 0 0 1px 0;
    border-radius: 20px;
  }

  hr.double {
    background: transparent;
    overflow: visible;
    /* For IE */
    padding: 0;
    border: none;
    border-top: medium double #333;
    color: #333;
    text-align: center;
  }

  hr.double:after {
    background: transparent;
    content: "§";
    display: inline-block;
    position: relative;
    top: -0.7em;
    font-size: 1.5em;
    padding: 0 0.25em;
  }

HTML

<div class="divider left">
  <hr />
  <label>Welcome!</label>
</div>
<p>&nbsp;</p>
<div class="divider right">
  <hr />
  <label>Welcome!</label>
</div>
<p>&nbsp;</p>
<div class="divider center">
  <hr />
  <label>Welcome!</label>
  <hr />
</div>
<p>&nbsp;</p>
<div class="divider left fixed">
  <hr />
  <label>Welcome!</label>
</div>
<p>&nbsp;</p>
<div class="divider right fixed">
  <hr />
  <label>Welcome!</label>
</div>
<p>&nbsp;</p>
<div class="divider center fixed">
  <hr />
  <label>Welcome!</label>
  <hr />
</div>

Or here's an interactive Fiddle: http://jsfiddle.net/mpyszenj/439/

create folder structure data/db in the working directory and then starting up mongodb using "mongod --dbpath data/db" works just fine

It work for me

$request = new Request();
$request->headers->set('content-type', 'application/json');     
$request->initialize(['yourParam' => 2]);

check output

$queryParams = $request->query();
dd($queryParams['yourParam']); // 2

Try this code

var x = [{prop1:"abc",prop2:"qwe"},{prop1:"bnmb",prop2:"yutu"},{prop1:"zxvz",prop2:"qwrq"}]
let index = x.findIndex(x => x.prop1 === 'zxvz')

Python has good options to scrape the web. The best one with a framework is scrapy. It can be a little tricky for beginners, so here is a little help.
1. Install python above 3.5 (lower ones till 2.7 will work).
2. Create a environment in conda ( I did this).
3. Install scrapy at a location and run in from there.
4. Scrapy shell will give you an interactive interface to test you code.
5. Scrapy startproject projectname will create a framework.
6. Scrapy genspider spidername will create a spider. You can create as many spiders as you want. While doing this make sure you are inside the project directory.

The easier one is to use requests and beautiful soup. Before starting give one hour of time to go through the documentation, it will solve most of your doubts. BS4 offer wide range of parsers that you can opt for. Use user-agent and sleep to make scraping easier. BS4 returns a bs.tag so use variable[0]. If there is js running, you wont be able to scrape using requests and bs4 directly. You could get the api link then parse the JSON to get the information you need or try selenium.

There is one trick with ParameterBag::get() method. You can set $deep parameter to true and access the required deep nested value without extra variable:

$request->request->get('form[some][deep][data]', null, true);

Also you have possibility to set a default value (2nd parameter of get() method), it can avoid redundant isset($form['some']['deep']['data']) call.

My problem was actually a problem of bad planning with the JSON object rather than an actual logic issue. What I ended up doing was organize the object as follows, per a suggestion from user2736012.

{
"dialog":
{
    "trunks":[
    {
        "trunk_id" : "1",
        "message": "This is just a JSON Test"
    },
    {
        "trunk_id" : "2",
        "message": "This is a test of a bit longer text. Hopefully this will at the very least create 3 lines and trigger us to go on to another box. So we can test multi-box functionality, too."
    }
    ]
}
}

At that point, I was able to do a fairly simple for loop based on the total number of objects.

var totalMessages = Object.keys(messages.dialog.trunks).length;

    for ( var i = 0; i < totalMessages; i++)
    {
        console.log("ID: " + messages.dialog.trunks[i].trunk_id + " Message " + messages.dialog.trunks[i].message);
    }

My method for getting totalMessages is not supported in all browsers, though. For my project, it actually doesn't matter, but beware of that if you choose to use something similar to this.

Have you tried the match() or charmatch() functions?

Example use:

match(c("A1", "A9", "A6"), myfile$Letter)

List<string> nameslist = new List<string> {"one", "two", "three"} ?

Here's a jQuery-ised function of Innuendo's answer, ready for use.

$.extend({
    keyCount : function(o) {
        if(typeof o == "object") {
            var i, count = 0;
            for(i in o) {
                if(o.hasOwnProperty(i)) {
                    count++;
                }
            }
            return count;
        } else {
            return false;
        }
    }
});

Can be called like this:

var cnt = $.keyCount({"foo" : "bar"}); //cnt = 1;

Using LIKE:

SELECT *
  FROM TABLE
 WHERE column LIKE '%cats%'  --case-insensitive

diff a1.txt a2.txt | grep '> ' | sed 's/> //' > a3.txt

I tried almost all the answers in this thread, but none was complete. After few trails above one worked for me. diff will give you difference but with some unwanted special charas. where you actual difference lines starts with '> '. so next step is to grep lines starts with '> 'and followed by removing the same with sed.

This one also removes tabs

$string = preg_replace('~[\r\n\t]+~', '', $text);

The one I like is: cd C:

To have linux like feel then do:

ln -s /cygdrive/c/folder ~/folder

and use this like: ~/folder/..

If you do not need speed, sockets are the easiest way to go!

If what you are looking at is speed, the fastest solution is shared Memory, not named pipes.

There is http://ptsv2.com/

"Here you will find a server which receives any POST you wish to give it and stores the contents for you to review."

The other answers mostly use the flags for setSystemUiVisibility() method in View. However, this API is deprecated since Android 11. Check my article about modifying the system UI visibility for more information. The article also explains how to handle the cutouts properly or how to listen to the visibility changes.

Here are code snippets for showing / hiding system bars with the new API as well as the deprecated one for backward compatibility:

/**
 * Hides the system bars and makes the Activity "fullscreen". If this should be the default
 * state it should be called from [Activity.onWindowFocusChanged] if hasFocus is true.
 * It is also recommended to take care of cutout areas. The default behavior is that the app shows
 * in the cutout area in portrait mode if not in fullscreen mode. This can cause "jumping" if the
 * user swipes a system bar to show it. It is recommended to set [WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_NEVER],
 * call [showBelowCutout] from [Activity.onCreate]
 * (see [Android Developers article about cutouts](https://developer.android.com/guide/topics/display-cutout#never_render_content_in_the_display_cutout_area)).
 * @see showSystemUI
 * @see addSystemUIVisibilityListener
 */
fun Activity.hideSystemUI() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
        window.insetsController?.let {
            // Default behavior is that if navigation bar is hidden, the system will "steal" touches
            // and show it again upon user's touch. We just want the user to be able to show the
            // navigation bar by swipe, touches are handled by custom code -> change system bar behavior.
            // Alternative to deprecated SYSTEM_UI_FLAG_IMMERSIVE.
            it.systemBarsBehavior = WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
            // make navigation bar translucent (alternative to deprecated
            // WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION)
            // - do this already in hideSystemUI() so that the bar
            // is translucent if user swipes it up
            window.navigationBarColor = getColor(R.color.internal_black_semitransparent_light)
            // Finally, hide the system bars, alternative to View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
            // and SYSTEM_UI_FLAG_FULLSCREEN.
            it.hide(WindowInsets.Type.systemBars())
        }
    } else {
        // Enables regular immersive mode.
        // For "lean back" mode, remove SYSTEM_UI_FLAG_IMMERSIVE.
        // Or for "sticky immersive," replace it with SYSTEM_UI_FLAG_IMMERSIVE_STICKY
        @Suppress("DEPRECATION")
        window.decorView.systemUiVisibility = (
                // Do not let system steal touches for showing the navigation bar
                View.SYSTEM_UI_FLAG_IMMERSIVE
                        // Hide the nav bar and status bar
                        or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_FULLSCREEN
                        // Keep the app content behind the bars even if user swipes them up
                        or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
        // make navbar translucent - do this already in hideSystemUI() so that the bar
        // is translucent if user swipes it up
        @Suppress("DEPRECATION")
        window.addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION)
    }
}

/**
 * Shows the system bars and returns back from fullscreen.
 * @see hideSystemUI
 * @see addSystemUIVisibilityListener
 */
fun Activity.showSystemUI() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
        // show app content in fullscreen, i. e. behind the bars when they are shown (alternative to
        // deprecated View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION and View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
        window.setDecorFitsSystemWindows(false)
        // finally, show the system bars
        window.insetsController?.show(WindowInsets.Type.systemBars())
    } else {
        // Shows the system bars by removing all the flags
        // except for the ones that make the content appear under the system bars.
        @Suppress("DEPRECATION")
        window.decorView.systemUiVisibility = (
                View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
    }
}

Or echo 'put {path to file}' | sftp {user}@{host}:{dir}, which would work in both unix and powershell.

The way you tried first is actually directly possible with numpy:

import numpy
myArray = numpy.array([10,20,30,40,50,60,70,80,90])
myInt = 10
newArray = myArray/myInt

If you do such operations with long lists and especially in any sort of scientific computing project, I would really advise using numpy.

colleagues.

I have faced with this trouble during a development of automation tests for our REST API. JDK 7_80 was installed at my machine only. Before I installed JDK 8, everything worked just fine and I had a possibility to obtain OAuth 2.0 tokens with a JMeter. After I installed JDK 8, the nightmare with Certificates does not conform to algorithm constraints began.

Both JMeter and Serenity did not have a possibility to obtain a token. JMeter uses the JDK library to make the request. The library just raises an exception when the library call is made to connect to endpoints that use it, ignoring the request.

The next thing was to comment all the lines dedicated to disabledAlgorithms in ALL java.security files.

C:\Java\jre7\lib\security\java.security
C:\Java\jre8\lib\security\java.security
C:\Java\jdk8\jre\lib\security\java.security
C:\Java\jdk7\jre\lib\security\java.security

Then it started to work at last. I know, that's a brute force approach, but it was the most simple way to fix it.

# jdk.tls.disabledAlgorithms=SSLv3, RC4, MD5withRSA, DH keySize < 768
# jdk.certpath.disabledAlgorithms=MD2, MD5, RSA keySize < 1024

You can create a UIView with the desired height (the width should be that of the UITableView), and inside it you can place a UIImageView with the picture of the proper dimensions: they won't stretch automatically.

You can also give margin above and below the inner UIImageView, by giving a higher height to the container view.

Additionally, you can assign a Translation transform in order to place the image in the middle of its container header view, for example.

Do NOT loop through all cells!! There is a lot of overhead in communications between worksheets and VBA, for both reading and writing. Looping through all cells will be agonizingly slow. I'm talking hours.

Instead, load an entire sheet at once into a Variant array. In Excel 2003, this takes about 2 seconds (and 250 MB of RAM). Then you can loop through it in no time at all.

In Excel 2007 and later, sheets are about 1000 times larger (1048576 rows × 16384 columns = 17 billion cells, compared to 65536 rows × 256 columns = 17 million in Excel 2003). You will run into an "Out of memory" error if you try to load the whole sheet into a Variant; on my machine I can only load 32 million cells at once. So you have to limit yourself to the range you know has actual data in it, or load the sheet bit by bit, e.g. 30 columns at a time.

Option Explicit

Sub test()

    Dim varSheetA As Variant
    Dim varSheetB As Variant
    Dim strRangeToCheck As String
    Dim iRow As Long
    Dim iCol As Long

    strRangeToCheck = "A1:IV65536"
    ' If you know the data will only be in a smaller range, reduce the size of the ranges above.
    Debug.Print Now
    varSheetA = Worksheets("Sheet1").Range(strRangeToCheck)
    varSheetB = Worksheets("Sheet2").Range(strRangeToCheck) ' or whatever your other sheet is.
    Debug.Print Now

    For iRow = LBound(varSheetA, 1) To UBound(varSheetA, 1)
        For iCol = LBound(varSheetA, 2) To UBound(varSheetA, 2)
            If varSheetA(iRow, iCol) = varSheetB(iRow, iCol) Then
                ' Cells are identical.
                ' Do nothing.
            Else
                ' Cells are different.
                ' Code goes here for whatever it is you want to do.
            End If
        Next iCol
    Next iRow

End Sub

To compare to a sheet in a different workbook, open that workbook and get the sheet as follows:

Set wbkA = Workbooks.Open(filename:="C:\MyBook.xls")
Set varSheetA = wbkA.Worksheets("Sheet1") ' or whatever sheet you need

BigDecimal is Oracle's arbitrary-precision numerical library. BigDecimal is part of the Java language and is useful for a variety of applications ranging from the financial to the scientific (that's where sort of am).

There's nothing wrong with using doubles for certain calculations. Suppose, however, you wanted to calculate Math.Pi * Math.Pi / 6, that is, the value of the Riemann Zeta Function for a real argument of two (a project I'm currently working on). Floating-point division presents you with a painful problem of rounding error.

BigDecimal, on the other hand, includes many options for calculating expressions to arbitrary precision. The add, multiply, and divide methods as described in the Oracle documentation below "take the place" of +, *, and / in BigDecimal Java World:

http://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html

The compareTo method is especially useful in while and for loops.

Be careful, however, in your use of constructors for BigDecimal. The string constructor is very useful in many cases. For instance, the code

BigDecimal onethird = new BigDecimal("0.33333333333");

utilizes a string representation of 1/3 to represent that infinitely-repeating number to a specified degree of accuracy. The round-off error is most likely somewhere so deep inside the JVM that the round-off errors won't disturb most of your practical calculations. I have, from personal experience, seen round-off creep up, however. The setScale method is important in these regards, as can be seen from the Oracle documentation.

For anyone looking to use this and keep the 'click' functionality (as John Landheer mentions in his comment), you can do it with just a couple of modifications:

Add a couple of globals:

var clickms = 100;
var lastTouchDown = -1;

Then modify the switch statement from the original to this:

var d = new Date();
switch(event.type)
{
    case "touchstart": type = "mousedown"; lastTouchDown = d.getTime(); break;
    case "touchmove": type="mousemove"; lastTouchDown = -1; break;        
    case "touchend": if(lastTouchDown > -1 && (d.getTime() - lastTouchDown) < clickms){lastTouchDown = -1; type="click"; break;} type="mouseup"; break;
    default: return;
}

You may want to adjust 'clickms' to your tastes. Basically it's just watching for a 'touchstart' followed quickly by a 'touchend' to simulate a click.

While base64 encoding is safe and one could argue "the right answer", I arrived here looking for a way to convert a Java byte array to/from a Java String as-is. That is, where each member of the byte array remains intact in its String counterpart, with no extra space required for encoding/transport.

This answer describing 8bit transparent encodings was very helpful for me. I used ISO-8859-1 on terabytes of binary data to convert back and forth successfully (binary <-> String) without the inflated space requirements needed for a base64 encoding, so is safe for my use-case - YMMV.

This was also helpful in explaining when/if you should experiment.

I presume that your problem with background-image is that it would be inefficient with a source for each image inside a stylesheet. My suggestion is to set the source inline:

<div style = 'background-image: url(image.gif)'></div>

div {
    background-repeat: no-repeat;
    background-position: 50%;
    border-radius: 50%;
    width: 100px;
    height: 100px;
}

Fiddle

Having problem with clock still showing even if I i wrote format: 'YYYY-MM-DD',

I hade to set pickTime: false and after change->hide I hade to focus->show

$('#VBS_RequiredDeliveryDate').datetimepicker({
  format: 'YYYY-MM-DD',
  pickTime: false
});

$('#VBS_RequiredDeliveryDate').on('change', function(){
    $('.datepicker').hide();
});

$('#VBS_RequiredDeliveryDate').on('focus', function(){
    $('.datepicker').show();
});

I am wondering when to use static methods?

1. A common use for static methods is to access static fields.

2. But you can have static methods, without referencing static variables. Helper methods without referring static variable can be found in some java classes like java.lang.Math

   public static int min(int a, int b) {
       return (a <= b) ? a : b;
   }
   

3. The other use case, I can think of these methods combined with synchronized method is implementation of class level locking in multi threaded environment.

Say if I have a class with a few getters and setters, a method or two, and I want those methods only to be invokable on an instance object of the class. Does this mean I should use a static method?

If you need to access method on an instance object of the class, your method should should be non static.

Oracle documentation page provides more details.

Not all combinations of instance and class variables and methods are allowed:

1. Instance methods can access instance variables and instance methods directly.
2. Instance methods can access class variables and class methods directly.
3. Class methods can access class variables and class methods directly.
4. Class methods cannot access instance variables or instance methods directly—they must use an object reference. Also, class methods cannot use the this keyword as there is no instance for this to refer to.

You need to call the AddAddress function once for each E-Mail address you want to send to. There are only two arguments for this function: recipient_email_address and recipient_name. The recipient name is optional and will not be used if not present.

$mailer->AddAddress('[email protected]', 'First Name');
$mailer->AddAddress('[email protected]', 'Second Name');
$mailer->AddAddress('[email protected]', 'Third Name');

You could use an array to store the recipients and then use a for loop. I hope it helps.

you can create a variable and send to ajax.

var m = { "Value": @Model.Value }

$.ajax({
    url: '<%=Url.Action("ModelPage")%>',
    type: "POST",
    data:  m,
    success: function(result) {
        $("div#updatePane").html(result);
    },

    complete: function() {
    $('form').onsubmit({ preventDefault: function() { } });

    }
});

All of model's field must bo ceated in m.

git.exe is common for any git based applications like GitHub, Bitbucket etc. Some times it is possible that you have already installed another git based application so git.exe will be present in the bin folder of that application.

For example if you installed bitbucket before github in your PC, you will find git.exe in C:\Users\{username}\AppData\Local\Atlassian\SourceTree\git_local\bin instead of C:\Users\{username}\AppData\Local\GitHub\PortableGit.....\bin.

BTW, HTTP 1/1 specification (RFC2616) suggests no more than 2 connections per server.

Clients that use persistent connections SHOULD limit the number of simultaneous connections that they maintain to a given server. A single-user client SHOULD NOT maintain more than 2 connections with any server or proxy. A proxy SHOULD use up to 2*N connections to another server or proxy, where N is the number of simultaneously active users. These guidelines are intended to improve HTTP response times and avoid congestion.

To use variables within a query you have to use bindValue() or bindParam(). And do not concatenate the variables with " . $variable . "

$statement = "SELECT count(account_id) FROM account
                  WHERE email = ? AND is_email_confirmed;";
$preparedStatement = $this->postgreSqlHandler->prepare($statement);
$preparedStatement->bindValue(1, $account->getEmail());
$preparedStatement->execute();
$numberRows= $preparedStatement->fetchColumn();

GL

You mention the most commonly implemented, which is Adjacency List: https://blogs.msdn.microsoft.com/mvpawardprogram/2012/06/25/hierarchies-convert-adjacency-list-to-nested-sets

There are other models as well, including materialized path and nested sets: http://communities.bmc.com/communities/docs/DOC-9902

Joe Celko has written a book on this subject, which is a good reference from a general SQL perspective (it is mentioned in the nested set article link above).

Also, Itzik Ben-Gann has a good overview of the most common options in his book "Inside Microsoft SQL Server 2005: T-SQL Querying".

The main things to consider when choosing a model are:

1) Frequency of structure change - how frequently does the actual structure of the tree change. Some models provide better structure update characteristics. It is important to separate structure changes from other data changes however. For example, you may want to model a company's organizational chart. Some people will model this as an adjacency list, using the employee ID to link an employee to their supervisor. This is usually a sub-optimal approach. An approach that often works better is to model the org structure separate from employees themselves, and maintain the employee as an attribute of the structure. This way, when an employee leaves the company, the organizational structure itself does not need to be changes, just the association with the employee that left.

2) Is the tree write-heavy or read-heavy - some structures work very well when reading the structure, but incur additional overhead when writing to the structure.

3) What types of information do you need to obtain from the structure - some structures excel at providing certain kinds of information about the structure. Examples include finding a node and all its children, finding a node and all its parents, finding the count of child nodes meeting certain conditions, etc. You need to know what information will be needed from the structure to determine the structure that will best fit your needs.

if you want to add the data in the increment order inside your associative array you can do this:

$newdata =  array (
      'wpseo_title' => 'test',
      'wpseo_desc' => 'test',
      'wpseo_metakey' => 'test'
    );

// for recipe

$md_array["recipe_type"][] = $newdata;

//for cuisine

 $md_array["cuisine"][] = $newdata;

this will get added to the recipe or cuisine depending on what was the last index.

Array push is usually used in the array when you have sequential index: $arr[0] , $ar[1].. you cannot use it in associative array directly. But since your sub array is had this kind of index you can still use it like this

array_push($md_array["cuisine"],$newdata);

There is also another solution to the problem by implementing a layer-list that will act as the background for the LinearLayoout.

Add background_with_shadow.xml file to res/drawable. Containing:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item >
        <shape 
            android:shape="rectangle">
        <solid android:color="@android:color/darker_gray" />
        <corners android:radius="5dp"/>
        </shape>
    </item>
    <item android:right="1dp" android:left="1dp" android:bottom="2dp">
        <shape 
            android:shape="rectangle">
        <solid android:color="@android:color/white"/>
        <corners android:radius="5dp"/>
        </shape>
    </item>
</layer-list>

Then add the the layer-list as background in your LinearLayout.

<LinearLayout
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:background="@drawable/background_with_shadow"/>

public class ImageButton extends JButton {

    protected ImageButton(){
    }

    @Override
        public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        Image img = Toolkit.getDefaultToolkit().getImage("water.bmp");

        g2.drawImage(img, 45, 35, this);
        g2.finalize();
    }
}

OR use this code

class MyButton extends JButton {

    Image image;
    ImageObserver imageObserver;


    MyButtonl(String filename) {
            super();
            ImageIcon icon = new ImageIcon(filename);
            image = icon.getImage();
            imageObserver = icon.getImageObserver();
        }

     public void paint( Graphics g ) {
            super.paint( g );
            g.drawImage(image,  0 , 0 , getWidth() , getHeight() , imageObserver);
        }
    }

You can do this:

@Override
protected Dialog onCreateDialog(int id) {
    String messageDialog;
    String valueOK;
    String valueCancel;
    String titleDialog;
    switch (id) {

    case id:
        titleDialog = itemTitle;
        messageDialog = itemDescription
        valueOK = "OK";            
        return new AlertDialog.Builder(HomeView.this).setTitle(titleDialog).setPositiveButton(valueOK, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                Log.d(this.getClass().getName(), "AlertItem");
            }
        }).setMessage(messageDialog).create(); 

and then call to

showDialog(numbreOfItem);

You can be more precise with CSS background-origin:

background-origin: content-box;

This will make image respect the padding of the box.

To specify the coordinates within the SVG image independently of the scaled size of the image, use the viewBox attribute on the SVG element to define what the bounding box of the image is in the coordinate system of the image, and use the width and height attributes to define what the width or height are with respect to the containing page.

For instance, if you have the following:

<svg>
    <polygon fill=red stroke-width=0 
             points="0,10 20,10 10,0" />
</svg>

It will render as a 10px by 20px triangle:

Now, if you set only the width and height, that will change the size of the SVG element, but not scale the triangle:

<svg width=100 height=50>
    <polygon fill=red stroke-width=0 
             points="0,10 20,10 10,0" />
</svg>

If you set the view box, that causes it to transform the image such that the given box (in the coordinate system of the image) is scaled up to fit within the given width and height (in the coordinate system of the page). For instance, to scale up the triangle to be 100px by 50px:

<svg width=100 height=50 viewBox="0 0 20 10">
    <polygon fill=red stroke-width=0 
             points="0,10 20,10 10,0" />
</svg>

If you want to scale it up to the width of the HTML viewport:

<svg width="100%" viewBox="0 0 20 10">
    <polygon fill=red stroke-width=0 
             points="0,10 20,10 10,0" />
</svg>

Note that by default, the aspect ratio is preserved. So if you specify that the element should have a width of 100%, but a height of 50px, it will actually only scale up to the height of 50px (unless you have a very narrow window):

<svg width="100%" height="50px" viewBox="0 0 20 10">
    <polygon fill=red stroke-width=0 
             points="0,10 20,10 10,0" />
</svg>

If you actually want it to stretch horizontally, disable aspect ratio preservation with preserveAspectRatio=none:

<svg width="100%" height="50px" viewBox="0 0 20 10" preserveAspectRatio="none">
    <polygon fill=red stroke-width=0 
             points="0,10 20,10 10,0" />
</svg>

(note that while in my examples I use syntax that works for HTML embedding, to include the examples as an image in StackOverflow I am instead embedding within another SVG, so I need to use valid XML syntax)

I recommend using the tiny javascript library Bowser, yes no r. It is based on the navigator.userAgent and quite well tested for all browsers including iphone, android etc.

https://github.com/ded/bowser

You can use simply say:

if (bowser.msie && bowser.version <= 6) {
  alert('Hello IE');
} else if (bowser.firefox){
  alert('Hello Foxy');
} else if (bowser.chrome){
  alert('Hello Chrome');
} else if (bowser.safari){
  alert('Hello Safari');
} else if(bowser.iphone || bowser.android){
  alert('Hello mobile');
}

You can give the background image in css :

#canvas { background:url(example.jpg) }

it will show you canvas back ground image

From http://psoug.org/reference/roles.html, create a procedure on your database for your user to do it:

CREATE OR REPLACE PROCEDURE GRANT_SELECT(to_user in varchar2) AS

  CURSOR ut_cur IS SELECT table_name FROM user_tables;

  RetVal  NUMBER;
  sCursor INT;
  sqlstr  VARCHAR2(250);

BEGIN
    FOR ut_rec IN ut_cur
    LOOP
      sqlstr := 'GRANT SELECT ON '|| ut_rec.table_name || ' TO ' || to_user;
      sCursor := dbms_sql.open_cursor;
      dbms_sql.parse(sCursor,sqlstr, dbms_sql.native);
      RetVal := dbms_sql.execute(sCursor);
      dbms_sql.close_cursor(sCursor);

    END LOOP;
END grant_select;

actually, your answer is not complete as the values also depend on the wrapping container. In case of relative or linear layouts, the values behave like this:

• EXACTLY match_parent is EXACTLY + size of the parent
• AT_MOST wrap_content results in an AT_MOST MeasureSpec
• UNSPECIFIED never triggered

In case of an horizontal scroll view, your code will work.

You should be able to use

IIF(Fields!ExitReason.Value = 7, 1, 0)

http://msdn.microsoft.com/en-us/library/ms157328.aspx

Load each query into a datatable:

http://www.dotnetcurry.com/ShowArticle.aspx?ID=143

load both datatables into the dataset:

http://msdn.microsoft.com/en-us/library/aeskbwf7%28v=vs.80%29.aspx

Add given code Service class for "OS >= Build.VERSION_CODES.O" in onCreate()

@Override
public void onCreate(){
    super.onCreate();

     .................................
     .................................

    //For creating the Foreground Service
    NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
    String channelId = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O ? getNotificationChannel(notificationManager) : "";
    NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, channelId);
    Notification notification = notificationBuilder.setOngoing(true)
            .setSmallIcon(R.mipmap.ic_launcher)
           // .setPriority(PRIORITY_MIN)
            .setCategory(NotificationCompat.CATEGORY_SERVICE)
            .build();

    startForeground(110, notification);
}



@RequiresApi(Build.VERSION_CODES.O)
private String getNotificationChannel(NotificationManager notificationManager){
    String channelId = "channelid";
    String channelName = getResources().getString(R.string.app_name);
    NotificationChannel channel = new NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_HIGH);
    channel.setImportance(NotificationManager.IMPORTANCE_NONE);
    channel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
    notificationManager.createNotificationChannel(channel);
    return channelId;
}

Add this permission in manifest file:

 <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

It can also be as simple as this.

@media (orientation: landscape) {

}

this code works well on my site because it detects whether its ie or not and activates the javascript if it is its below you can check it out live on ie or other browser Just a demo of the if ie javascript in action

<script type="text/javascript">
<!--[if IE]>
window.location.href = "http://yoursite.com/";
<![endif]-->
</script>

Just as a matter of fact:

data_joined = dat1.join(dat2)
print(data_joined)

Send the data from the form:

$("#change_section_type").live "change", ->
url = $(this).attr("data-url")
postData = $(this).parents("#contract_setting_form").serializeArray()
$.ajax
  type: "PUT"
  url: url
  dataType: "script"
  data: postData

for CMake remove/disable with_libv4l with_v4l variables if you do not need this lib.

I think you are looking for UPDATE and not insert?

UPDATE `users`
SET `username` = 'Jack', `password` = '123'
WHERE `id` = 1

For me none of the above solutions worked (reinstalling, clearing cache, folders etc.).

My problem was solved with:

npm config set registry https://registry.npmjs.org/

CSS relates to visual styling and not behaviour, so the answer is no really.

You could however either use javascript to modify the behaviour or change the styling of the span in question so that it doesn't have the pointy finger, underline, etc. Styling it like that will still leave it clickable.

Even better, change your markup so that it reflects what you want it to do.

If you use the nextLine() method immediately following the nextInt() method, nextInt() reads integer tokens; because of this, the last newline character for that line of integer input is still queued in the input buffer and the next nextLine() will be reading the remainder of the integer line (which is empty). So we read can read the empty space to another string might work. Check below code.

import java.util.Scanner;

public class Solution {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        int i = scan.nextInt();
        Double d = scan.nextDouble();
        String f = scan.nextLine();
        String s = scan.nextLine();


        // Write your code here.

        System.out.println("String: " + s);
        System.out.println("Double: " + d);
         System.out.println("Int: " + i);
    }
}

This array_group_by function achieves what you are looking for:

$grouped = array_group_by($arr, 'id');

It even supports multi-level groupings:

$grouped = array_group_by($arr, 'id', 'part_no');

strcpy example:

#include <stdio.h>
#include <string.h>

int main ()
{
  char str1[]="Sample string" ;
  char str2[40] ;
  strcpy (str2,str1) ;
  printf ("str1: %s\n",str1) ;
  return 0 ;
}

Output: str1: Sample string

Your case:

A simple = operator should do the job.

string str1="Sample string" ;
string str2 = str1 ;

Yes, a menu gives you the bar but it doesn't give you any items to put in the bar. You need something like (from one of my own projects):

<!-- Menu. -->
<Menu Width="Auto" Height="20" Background="#FFA9D1F4" DockPanel.Dock="Top">
    <MenuItem Header="_Emulator">
    <MenuItem Header="Load..." Click="MenuItem_Click" />
    <MenuItem Header="Load again" Click="menuEmulLoadLast" />
    <Separator />
    <MenuItem Click="MenuItem_Click">
        <MenuItem.Header>
            <DockPanel>
                <TextBlock>Step</TextBlock>
                <TextBlock Width="10"></TextBlock>
                <TextBlock HorizontalAlignment="Right">F2</TextBlock>
            </DockPanel>
        </MenuItem.Header>
    </MenuItem>
    :

1. Open SDK Manager and download Intel x86 Emulator Accelerator (HAXM installer) if you haven't.

2. Now go to your SDK directory (C:\users\username\AppData\Local\Android\sdk, generally). In this directory, go to extras ? Intel ? Hardware_Accelerated_Execution_Manager and run the file named "intelhaxm-android.exe".

   In case you get an error like "Intel virtualization technology (vt,vt-x) is not enabled", go to your BIOS settings and enable hardware virtualization.

3. Restart Android Studio and then try to start the AVD again.

It might take a minute or 2 to show the emulator window.

Switch to preg_replace^Docs and update the expression to use preg syntax (PCRE) instead of ereg syntax (POSIX) where there are differences^Docs (just as it says to do in the manual for ereg_replace^Docs).

You need MouseClick instead of Click event handler, reference.

switch (e.Button) {

    case MouseButtons.Left:
    // Left click
    break;

    case MouseButtons.Right:
    // Right click
    break;
    ...
}

I have just been in a similar position with regards to setting the 777 permissions on the apache website hosting directory. After a little bit of tinkering it seems that changing the group ownership of the folder to the "apache" group allowed access to the folder based on the user group.

1) make sure that the group ownership of the folder is set to the group apache used / generates for use. (check /etc/groups, mine was www-data on Ubuntu)

2) set the folder permissions to 774 to stop "everyone" from having any change access, but allowing the owner and group permissions required.

3) add your user account to the group that has permission on the folder (mine was www-data).

Another solution that doesn't not require to hard-code the receiving app and that is therefore safer:

Intent intent = new Intent(Intent.ACTION_INSTALL_PACKAGE);
intent.setData( Uri.fromFile(new File(pathToApk)) );
startActivity(intent);

You can use regular expresion as follows:

return Regex.Replace(strIn, @"[^\w\.@-]", "", RegexOptions.None, TimeSpan.FromSeconds(1.0));

Here's a little cmd script you can copy-n-paste into a file named something like where.cmd:

@echo off
rem - search for the given file in the directories specified by the path, and display the first match
rem
rem    The main ideas for this script were taken from Raymond Chen's blog:
rem
rem         http://blogs.msdn.com/b/oldnewthing/archive/2005/01/20/357225.asp
rem
rem
rem - it'll be nice to at some point extend this so it won't stop on the first match. That'll
rem     help diagnose situations with a conflict of some sort.
rem

setlocal

rem - search the current directory as well as those in the path
set PATHLIST=.;%PATH%
set EXTLIST=%PATHEXT%

if not "%EXTLIST%" == "" goto :extlist_ok
set EXTLIST=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH
:extlist_ok

rem - first look for the file as given (not adding extensions)
for %%i in (%1) do if NOT "%%~$PATHLIST:i"=="" echo %%~$PATHLIST:i

rem - now look for the file adding extensions from the EXTLIST
for %%e in (%EXTLIST%) do @for %%i in (%1%%e) do if NOT "%%~$PATHLIST:i"=="" echo %%~$PATHLIST:i

You can't access non-static members from a static method. (Note that Main() is static, which is a requirement of .Net). Just make siprimo and volteado static, by placing the static keyword in front of them. e.g.:

 static private long volteado(long a)

NullPointerExceptions are among the easier exceptions to diagnose, frequently. Whenever you get an exception in Java and you see the stack trace ( that's what your second quote-block is called, by the way ), you read from top to bottom. Often, you will see exceptions that start in Java library code or in native implementations methods, for diagnosis you can just skip past those until you see a code file that you wrote.

Then you like at the line indicated and look at each of the objects ( instantiated classes ) on that line -- one of them was not created and you tried to use it. You can start by looking up in your code to see if you called the constructor on that object. If you didn't, then that's your problem, you need to instantiate that object by calling new Classname( arguments ). Another frequent cause of NullPointerExceptions is accidentally declaring an object with local scope when there is an instance variable with the same name.

In your case, the exception occurred in your constructor for Workshop on line 75. <init> means the constructor for a class. If you look on that line in your code, you'll see the line

denimjeansButton.addItemListener(this);

There are fairly clearly two objects on this line: denimjeansButton and this. this is synonymous with the class instance you are currently in and you're in the constructor, so it can't be this. denimjeansButton is your culprit. You never instantiated that object. Either remove the reference to the instance variable denimjeansButton or instantiate it.

If you end up with none of the above working, you might be able to retrieve data using the suggestion from here: http://www.spinics.net/lists/git/msg62499.html

git prune -n
git cat-file -p <blob #>

In a nutshell Javascript Closures allow a function to access a variable that is declared in a lexical-parent function.

Let's see a more detailed explanation. To understand closures it is important to understand how JavaScript scopes variables.

Scopes

In JavaScript scopes are defined with functions. Every function defines a new scope.

Consider the following example;

function f()
{//begin of scope f
  var foo='hello'; //foo is declared in scope f
  for(var i=0;i<2;i++){//i is declared in scope f
     //the for loop is not a function, therefore we are still in scope f
     var bar = 'Am I accessible?';//bar is declared in scope f
     console.log(foo);
  }
  console.log(i);
  console.log(bar);
}//end of scope f

calling f prints

hello
hello
2
Am I Accessible?

Let's now consider the case we have a function g defined within another function f.

function f()
{//begin of scope f
  function g()
  {//being of scope g
    /*...*/
  }//end of scope g
  /*...*/
}//end of scope f

We will call f the lexical parent of g. As explained before we now have 2 scopes; the scope f and the scope g.

But one scope is "within" the other scope, so is the scope of the child function part of the scope of the parent function? What happens with the variables declared in the scope of the parent function; will I be able to access them from the scope of the child function? That's exactly where closures step in.

Closures

In JavaScript the function g can not only access any variables declared in scope g but also access any variables declared in the scope of the parent function f.

Consider following;

function f()//lexical parent function
{//begin of scope f
  var foo='hello'; //foo declared in scope f
  function g()
  {//being of scope g
    var bar='bla'; //bar declared in scope g
    console.log(foo);
  }//end of scope g
  g();
  console.log(bar);
}//end of scope f

calling f prints

hello
undefined

Let's look at the line console.log(foo);. At this point we are in scope g and we try to access the variable foo that is declared in scope f. But as stated before we can access any variable declared in a lexical parent function which is the case here; g is the lexical parent of f. Therefore hello is printed.
Let's now look at the line console.log(bar);. At this point we are in scope f and we try to access the variable bar that is declared in scope g. bar is not declared in the current scope and the function g is not the parent of f, therefore bar is undefined

Actually we can also access the variables declared in the scope of a lexical "grand parent" function. Therefore if there would be a function h defined within the function g

function f()
{//begin of scope f
  function g()
  {//being of scope g
    function h()
    {//being of scope h
      /*...*/
    }//end of scope h
    /*...*/
  }//end of scope g
  /*...*/
}//end of scope f

then h would be able to access all the variables declared in the scope of function h, g, and f. This is done with closures. In JavaScript closures allows us to access any variable declared in the lexical parent function, in the lexical grand parent function, in the lexical grand-grand parent function, etc. This can be seen as a scope chain; scope of current function -> scope of lexical parent function -> scope of lexical grand parent function -> ... until the last parent function that has no lexical parent.

The window object

Actually the chain doesn't stop at the last parent function. There is one more special scope; the global scope. Every variable not declared in a function is considered to be declared in the global scope. The global scope has two specialities;

• every variable declared in the global scope is accessible everywhere
• the variables declared in the global scope correspond to the properties of the window object.

Therefore there are exactly two ways of declaring a variable foo in the global scope; either by not declaring it in a function or by setting the property foo of the window object.

Both attempts uses closures

Now that you have read a more detailed explanation it may now be apparent that both solutions uses closures. But to be sure, let's make a proof.

Let's create a new Programming Language; JavaScript-No-Closure. As the name suggests, JavaScript-No-Closure is identical to JavaScript except it doesn't support Closures.

In other words;

var foo = 'hello';
function f(){console.log(foo)};
f();
//JavaScript-No-Closure prints undefined
//JavaSript prints hello

Alright, let's see what happens with the first solution with JavaScript-No-Closure;

for(var i = 0; i < 10; i++) {
  (function(){
    var i2 = i;
    setTimeout(function(){
        console.log(i2); //i2 is undefined in JavaScript-No-Closure 
    }, 1000)
  })();
}

therefore this will print undefined 10 times in JavaScript-No-Closure.

Hence the first solution uses closure.

Let's look at the second solution;

for(var i = 0; i < 10; i++) {
  setTimeout((function(i2){
    return function() {
        console.log(i2); //i2 is undefined in JavaScript-No-Closure
    }
  })(i), 1000);
}

therefore this will print undefined 10 times in JavaScript-No-Closure.

Both solutions uses closures.

Edit: It is assumed that these 3 code snippets are not defined in the global scope. Otherwise the variables foo and i would be bind to the window object and therefore accessible through the window object in both JavaScript and JavaScript-No-Closure.

sc delete Apache2.4

Remove service in windows

Just a tip.. Temporary tables in Oracle are different to SQL Server. You create it ONCE and only ONCE, not every session. The rows you insert into it are visible only to your session, and are automatically deleted (i.e., TRUNCATE, not DROP) when you end you session ( or end of the transaction, depending on which "ON COMMIT" clause you use).

You are probably hit by this bug which prevents the Android Gradle Plugin from automatically adding the "Android Support Repository" to the list of Gradle repositories. The work-around, as mentioned in the bug report, is to explicitly add the m2repository directory as a local Maven directory in the top-level build.gradle file as follows:

allprojects {
    repositories {
        // Work around https://code.google.com/p/android/issues/detail?id=69270.
        def androidHome = System.getenv("ANDROID_HOME")
        maven {
            url "$androidHome/extras/android/m2repository/"
        }
    }
}

And a PHP example, multiple matching lines will be displayed:

<?php
$file = 'somefile.txt';
$searchfor = 'name';

// the following line prevents the browser from parsing this as HTML.
header('Content-Type: text/plain');

// get the file contents, assuming the file to be readable (and exist)
$contents = file_get_contents($file);
// escape special characters in the query
$pattern = preg_quote($searchfor, '/');
// finalise the regular expression, matching the whole line
$pattern = "/^.*$pattern.*\$/m";
// search, and store all matching occurences in $matches
if(preg_match_all($pattern, $contents, $matches)){
   echo "Found matches:\n";
   echo implode("\n", $matches[0]);
}
else{
   echo "No matches found";
}

It is mainly a performance issue.

Having strings behave LIKE value type helps when writing code, but having it BE a value type would make a huge performance hit.

For an in-depth look, take a peek at a nice article on strings in the .net framework.

On my AWS beanstalk server, I don't see $_SERVER['HTTPS'] variable. I do see $_SERVER['HTTP_X_FORWARDED_PROTO'] which can be either 'http' or 'https' so if you're hosting on AWS, use this:

if ($_SERVER['HTTP_HOST'] != 'localhost' and $_SERVER['HTTP_X_FORWARDED_PROTO'] != "https") {
    $location = 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
    header('HTTP/1.1 301 Moved Permanently');
    header('Location: ' . $location);
    exit;
}

Open a windows command line. Switch directories to C:\Windows\Microsoft.Net\Framework\v4.0.xxxx where the x's are the build number. Type aspnet_regiis -ir and hit enter. This should register .Net v4.0 and create the application pools by default. If it doesn't, you will need to create them manually by right-clicking the Application Pools folder in IIS and choosing Add Application Pool.

Edit: As a reference, please refer to the section of the linked document referring to the -i argument.

http://msdn.microsoft.com/en-us/library/k6h9cz8h.aspx

Its depend. If you have more than two images in .column but you only need some images to have css applied then its better to add class to image directly instead of doing .column img{/*styling for image here*/}

In performance aspect i thing apply class to image is better because by doing so css will not look for possible child image.

Adding to Cheeken's answer, This is how you sort a list of tuples by the 2nd item in descending order.

sorted([('abc', 121),('abc', 231),('abc', 148), ('abc',221)],key=lambda x: x[1], reverse=True)

The 'react-json-view' provides solution rendering json string.

import ReactJson from 'react-json-view';
<ReactJson src={my_important_json} theme="monokai" />

Typically for local variables I initialize them as late as I can. It's rare that I need a "dummy" value. However, if you do, you can use any value you like - it won't make any difference, if you're sure you're going to assign a value before reading it.

If you want the char equivalent of 0, it's just Unicode 0, which can be written as

char c = '\0';

That's also the default value for an instance (or static) variable of type char.

I know it is very late at the day to throw an answer at this one but I found that none of the answers were as useful to me as my own solution. A very simple way to get the path from your CWD to your bin folder is like this:

int main(int argc, char* argv[])
{
    std::string argv_str(argv[0]);
    std::string base = argv_str.substr(0, argv_str.find_last_of("/"));
}

You can now just use this as a base for your relative path. So for example I have this directory structure:

main
  ----> test
  ----> src
  ----> bin

and I want to compile my source code to bin and write a log to test I can just add this line to my code.

std::string pathToWrite = base + "/../test/test.log";

I have tried this approach on Linux using full path, alias etc. and it works just fine.

NOTE:

If you are on windows you should use a '\' as the file separator not '/'. You will have to escape this too for example:

std::string base = argv[0].substr(0, argv[0].find_last_of("\\"));

I think this should work but haven't tested, so comment would be appreciated if it works or a fix if not.

As Stein says, you can use the prototype javascript library from http://www.prototypejs.org. Include the JS and it is very simple then, $('formName').serialize() will return what you want!

Ensure the below folders in storage directory:

• logs
• framework
• framework/cache
• framework/cache/data
• framework/sessions
• framework/testing
• framework/views

Below is a command-line snippet that does for you

cd storage
mkdir logs
mkdir framework
mkdir framework/cache && framework/cache/data
mkdir framework/sessions
mkdir framework/testing
mkdir framework/views
chgrp -R www-data ../storage
chown -R www-data ../storage

@mattis is correct that iOS 10 Safari won't allow you to disable pinch to zoom with the user-scalable attribute. However, I got it to disable using preventDefault on the 'gesturestart' event. I've only verified this on Safari in iOS 10.0.2.

document.addEventListener('gesturestart', function (e) {
    e.preventDefault();
});

The Fill function uses a DataReader internally. If your consideration is "Which one is more efficient?", then using a DataReader in a tight loop that populates a collection record-by-record, is likely to be the same load on the system as using DataAdapter.Fill.

(System.Data.dll, System.Data.Common.DbDataAdapter, FillInternal.)

As was stated in the comments to the original post, this seemed to be an issue with the python interpreter I was using for whatever reason, and not something wrong with the python scripts. I switched over from the WinPython bundle to the official python 3.6 from python.org and it worked just fine. thanks for the help everyone :)

I had this problem after upgrading from Android Studio 2.3 to 3.0. As simple as it sounds, I actually just restarted my phone to fix it.

My guess is that the adb server on the phone somehow cached something from the previous installation of android studio, maybe a connection object or something, and by restarting the adb server it resolved the issue.

I hope this helps someone.

You need to create a structure like this:

public class Friends
{

    public List<FacebookFriend> data {get; set;}
}

public class FacebookFriend
{

    public string id {get; set;}
    public string name {get; set;}
}

Then you should be able to do:

Friends facebookFriends = new JavaScriptSerializer().Deserialize<Friends>(result);

The names of my classes are just an example. You should use proper names.

Adding a sample test:

string json =
    @"{""data"":[{""id"":""518523721"",""name"":""ftyft""}, {""id"":""527032438"",""name"":""ftyftyf""}, {""id"":""527572047"",""name"":""ftgft""}, {""id"":""531141884"",""name"":""ftftft""}]}";

Friends facebookFriends = new System.Web.Script.Serialization.JavaScriptSerializer().Deserialize<Friends>(json);

foreach(var item in facebookFriends.data)
{
    Console.WriteLine("id: {0}, name: {1}", item.id, item.name);
}

Produces:

id: 518523721, name: ftyft
id: 527032438, name: ftyftyf
id: 527572047, name: ftgft
id: 531141884, name: ftftft

Paul Randal has an exccellent discussion of this problem on his blog: http://www.sqlskills.com/blogs/paul/post/backup-log-with-no_log-use-abuse-and-undocumented-trace-flags-to-stop-it.aspx

We can write something like this. I have used with python-3.7.x

import sys

def print_fn():
    print("Hi")

def sum_fn(a, b):
    print(a + b)

if __name__ == "__main__":
    args = sys.argv
    # args[0] = current file
    # args[1] = function name
    # args[2:] = function args : (*unpacked)
    globals()[args[1]](*args[2:])

python demo.py print_fn
python demo.py sum_fn 5 8

Here is my version of function that is returning standard System.Diagnostics.Process with 3 new properties

Function Execute-Command ($commandTitle, $commandPath, $commandArguments)
{
    Try {
        $pinfo = New-Object System.Diagnostics.ProcessStartInfo
        $pinfo.FileName = $commandPath
        $pinfo.RedirectStandardError = $true
        $pinfo.RedirectStandardOutput = $true
        $pinfo.UseShellExecute = $false
        $pinfo.WindowStyle = 'Hidden'
        $pinfo.CreateNoWindow = $True
        $pinfo.Arguments = $commandArguments
        $p = New-Object System.Diagnostics.Process
        $p.StartInfo = $pinfo
        $p.Start() | Out-Null
        $stdout = $p.StandardOutput.ReadToEnd()
        $stderr = $p.StandardError.ReadToEnd()
        $p.WaitForExit()
        $p | Add-Member "commandTitle" $commandTitle
        $p | Add-Member "stdout" $stdout
        $p | Add-Member "stderr" $stderr
    }
    Catch {
    }
    $p
}

Say the other guy created bar on top of foo, but you created baz in the meantime and then merged, giving a history of

$ git lola
*   2582152 (HEAD, master) Merge branch 'otherguy'
|\  
| * c7256de (otherguy) bar
* | b7e7176 baz
|/  
* 9968f79 foo

Note: git lola is a non-standard but useful alias.

No dice with git revert:

$ git revert HEAD
fatal: Commit 2582152... is a merge but no -m option was given.

Charles Bailey gave an excellent answer as usual. Using git revert as in

$ git revert --no-edit -m 1 HEAD
[master e900aad] Revert "Merge branch 'otherguy'"
 0 files changed, 0 insertions(+), 0 deletions(-)
 delete mode 100644 bar

effectively deletes bar and produces a history of

$ git lola
* e900aad (HEAD, master) Revert "Merge branch 'otherguy'"
*   2582152 Merge branch 'otherguy'
|\  
| * c7256de (otherguy) bar
* | b7e7176 baz
|/  
* 9968f79 foo

But I suspect you want to throw away the merge commit:

$ git reset --hard HEAD^
HEAD is now at b7e7176 baz

$ git lola
* b7e7176 (HEAD, master) baz
| * c7256de (otherguy) bar
|/  
* 9968f79 foo

As documented in the git rev-parse manual

<rev>^, e.g. HEAD^, v1.5.1^0
A suffix ^ to a revision parameter means the first parent of that commit object. ^<n> means the n-th parent (i.e. <rev>^ is equivalent to <rev>^1). As a special rule, <rev>^0 means the commit itself and is used when <rev> is the object name of a tag object that refers to a commit object.

so before invoking git reset, HEAD^ (or HEAD^1) was b7e7176 and HEAD^2 was c7256de, i.e., respectively the first and second parents of the merge commit.

Be careful with git reset --hard because it can destroy work.

Try this code:

$(document).ready(function(){
    $('#YourControlID').click(function(){
        if() { //your condition
            $.messager.show({  
                title:'My Title',  
                msg:'The message content',  
                showType:'fade',  
                style:{  
                    right:'',  
                    bottom:''  
                }  
            });  
        }
    });
});

You can use a special designated object as the null object in case of references as follows:

class SomeClass
{
    public:

        int operator==(SomeClass &object)
        {
            if(this == &object) 
            {
                    return true;
            }

            return false;
        }


    static SomeClass NullObject;
};

SomeClass SomeClass::NullObject;

void print(SomeClass &val)
{
    if(val == SomeClass::NullObject)
    {
        printf("\nNULL");
    }
    else
    {
        printf("\nNOT NULL");
    }
}

A good friend and colleague of mine showed me how you can also use an IF block with SQL functions OBJECT_ID and COLUMNPROPERTY in SQL SERVER 2005+ to check for a column. You can use something similar to the following:

You can see for yourself here

IF (OBJECT_ID(N'[dbo].[myTable]') IS NOT NULL AND
    COLUMNPROPERTY( OBJECT_ID(N'[dbo].[myTable]'), 'ThisColumnDoesNotExist', 'ColumnId') IS NULL)
BEGIN
    SELECT 'Column does not exist -- You can add TSQL to add the column here'
END

Well, I'll try yet another code sample:

/**
 * Calculates the number of FULL days between to dates
 * @param startDate must be before endDate
 * @param endDate must be after startDate
 * @return number of day between startDate and endDate
 */
public static int daysBetween(Calendar startDate, Calendar endDate) {
    long start = startDate.getTimeInMillis();
    long end = endDate.getTimeInMillis();
    // It's only approximation due to several bugs (@see java.util.Date) and different precision in Calendar chosen
    // by user (ex. day is time-quantum).
    int presumedDays = (int) TimeUnit.MILLISECONDS.toDays(end - start);
    startDate.add(Calendar.DAY_OF_MONTH, presumedDays);
    // if we still didn't reach endDate try it with the step of one day
    if (startDate.before(endDate)) {
        startDate.add(Calendar.DAY_OF_MONTH, 1);
        ++presumedDays;
    }
    // if we crossed endDate then we must go back, because the boundary day haven't completed yet
    if (startDate.after(endDate)) {
        --presumedDays;
    }
    return presumedDays;
}

Just an FYI, you don't need to use CSS classes to accomplish this.

You can write the following line of code to get the correct control name on the client:

$("#<%= statusDDL.ClientID %>").val("2");

ASP.NET will render the control ID correctly inside the jQuery.

to preserve the console output, that is, write to a file and also have it displayed on the console, you could use a class like:

    public class TeePrintStream extends PrintStream {
        private final PrintStream second;

        public TeePrintStream(OutputStream main, PrintStream second) {
            super(main);
            this.second = second;
        }

        /**
         * Closes the main stream. 
         * The second stream is just flushed but <b>not</b> closed.
         * @see java.io.PrintStream#close()
         */
        @Override
        public void close() {
            // just for documentation
            super.close();
        }

        @Override
        public void flush() {
            super.flush();
            second.flush();
        }

        @Override
        public void write(byte[] buf, int off, int len) {
            super.write(buf, off, len);
            second.write(buf, off, len);
        }

        @Override
        public void write(int b) {
            super.write(b);
            second.write(b);
        }

        @Override
        public void write(byte[] b) throws IOException {
            super.write(b);
            second.write(b);
        }
    }

and used as in:

    FileOutputStream file = new FileOutputStream("test.txt");
    TeePrintStream tee = new TeePrintStream(file, System.out);
    System.setOut(tee);

(just an idea, not complete)

You can use org.apache.commons.math.util.MathUtils from apache common

double round = MathUtils.round(double1, 2, BigDecimal.ROUND_HALF_DOWN);

Change it to this:

var email = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i;

This is a regular expression literal that is passed the i flag which means to be case insensitive.

Keep in mind that email address validation is hard (there is a 4 or 5 page regular expression at the end of Mastering Regular Expressions demonstrating this) and your expression certainly will not capture all valid e-mail addresses.

Do you want the JDK or the JRE? Anyways, I had this problem too, a few weeks ago. I followed the instructions here and it worked:

http://www.backtrack-linux.org/wiki/index.php/Java_Install

NOTE: Before installing Java make sure you kill Firefox.

root@bt:~# killall -9 /opt/firefox/firefox-bin

You can download java from the official website. (Download tar.gz version)

We first create the directory and place java there:

root@bt:~# mkdir /opt/java

root@bt:~# mv -f jre1.7.0_05/ /opt/java/

Final changes.

root@bt:~# update-alternatives --install /usr/bin/java java /opt/java/jre1.7.0_05/bin/java 1

root@bt:~# update-alternatives --set java /opt/java/jre1.7.0_05/bin/java

root@bt:~# export JAVA_HOME="/opt/java/jre1.7.0_05"

Adding the plugin to Firefox.

For Java 7 (32 bit)

root@bt:~# ln -sf $JAVA_HOME/lib/i386/libnpjp2.so /usr/lib/mozilla/plugins/

For Java 8 (64 bit)

root@bt:~# ln -sf $JAVA_HOME/jre/lib/amd64/libnpjp2.so /usr/lib/mozilla/plugins/

Testing the plugin.

root@bt:~# firefox http://java.com/en/download/testjava.jsp

Views can:

• Simplify a complex table structure
• Simplify your security model by allowing you to filter sensitive data and assign permissions in a simpler fashion
• Allow you to change the logic and behavior without changing the output structure (the output remains the same but the underlying SELECT could change significantly)
• Increase performance (Sql Server Indexed Views)
• Offer specific query optimization with the view that might be difficult to glean otherwise

And you should not design tables to match views. Your base model should concern itself with efficient storage and retrieval of the data. Views are partly a tool that mitigates the complexities that arise from an efficient, normalized model by allowing you to abstract that complexity.

Also, asking "what are the advantages of using a view over a table? " is not a great comparison. You can't go without tables, but you can do without views. They each exist for a very different reason. Tables are the concrete model and Views are an abstracted, well, View.

with git 1.7, there's a really easy way using git rebase:

stage your files:

git add $files

create a new commit and re-use commit message of your "broken" commit

git commit -c master~4

prepend fixup! in the subject line (or squash! if you want to edit commit (message)):

fixup! Factored out some common XPath Operations

use git rebase -i --autosquash to fixup your commit

Just initialize an array and push the element on the array. It will automatic scale the array.

var a = [ ];

a.push('Some string'); console.log(a); // ['Some string'] 
a.push('another string'); console.log(a); // ['Some string', 'another string'] 
a.push('Some string'); console.log(a); // ['Some string', 'another string', 'Some string']

Minor variation of phillfri's answer which was already a variation of Geoff's answer: I added the ability to handle completely empty tables that contain no data for the Array Code.

Sub AddDataRow(tableName As String, NewData As Variant)
    Dim sheet As Worksheet
    Dim table As ListObject
    Dim col As Integer
    Dim lastRow As Range

    Set sheet = Range(tableName).Parent
    Set table = sheet.ListObjects.Item(tableName)

    'First check if the last row is empty; if not, add a row
    If table.ListRows.Count > 0 Then
        Set lastRow = table.ListRows(table.ListRows.Count).Range
        If Application.CountBlank(lastRow) < lastRow.Columns.Count Then
            table.ListRows.Add
        End If
    End If

    'Iterate through the last row and populate it with the entries from values()
    If table.ListRows.Count = 0 Then 'If table is totally empty, set lastRow as first entry
        table.ListRows.Add Position:=1
        Set lastRow = table.ListRows(1).Range
    Else
        Set lastRow = table.ListRows(table.ListRows.Count).Range
    End If
    For col = 1 To lastRow.Columns.Count
        If col <= UBound(NewData) + 1 Then lastRow.Cells(1, col) = NewData(col - 1)
    Next col
End Sub

Because abstract classes have state (fields) and somethimes they need to be initialized somehow.

From the fine manual:

ALTER TABLE mytable ALTER COLUMN mycolumn DROP NOT NULL;

There's no need to specify the type when you're just changing the nullability.

Ross, you can use Arrays.copyof() or Arrays.copyOfRange() too.

Integer[] integerArray = Arrays.copyOf(a, a.length, Integer[].class);
Integer[] integerArray = Arrays.copyOfRange(a, 0, a.length, Integer[].class);

Here the reason to hitting an ClassCastException is you can't treat an array of Integer as an array of Object. Integer[] is a subtype of Object[] but Object[] is not a Integer[].

And the following also will not give an ClassCastException.

Object[] a = new Integer[1];
Integer b=1;
a[0]=b;
Integer[] c = (Integer[]) a;

Use scrollTop() to get or set the scroll position.

The Code part :

Image imProfile = new Image(getClass().getResourceAsStream("/img/profile128.png"));

ImageView profileImage=new ImageView(imProfile);

in a javafx maven:

Addressing the above "too small a task to require a library" issue by a straightforward implementation:

def sizeof_fmt(num, suffix='B'):
    for unit in ['','Ki','Mi','Gi','Ti','Pi','Ei','Zi']:
        if abs(num) < 1024.0:
            return "%3.1f%s%s" % (num, unit, suffix)
        num /= 1024.0
    return "%.1f%s%s" % (num, 'Yi', suffix)

Supports:

• all currently known binary prefixes
• negative and positive numbers
• numbers larger than 1000 Yobibytes
• arbitrary units (maybe you like to count in Gibibits!)

Example:

>>> sizeof_fmt(168963795964)
'157.4GiB'

by Fred Cirera

Try below code using RJSONIO in console

library(RJSONIO)
library(RCurl)


json_file = getURL("https://raw.githubusercontent.com/isrini/SI_IS607/master/books.json")

json_file2 = RJSONIO::fromJSON(json_file)

head(json_file2)

If the project is maven placed it in src/main/resources, in the package phase it will copy it in ../WEB-INF/classes/hibernate.cfg.xml

Maybe call Directory.GetParent in a loop? That's if you want the full path to each directory and not just the directory names.

I use this solution having max(date_entered) and it works very well

SELECT 
  report_id, 
  computer_id, 
  date_entered
FROM reports
GROUP BY computer_id having max(date_entered)

Right now it will only work in some browsers, and as far as I can see you haven't actually linked to a file, so that would explain why it is not playing.

but as you want a live stream (which I have not tested with)

check out Streaming via RTSP or RTP in HTML5

and http://www.streamingmedia.com/Articles/Editorial/Featured-Articles/25-HTML5-Video-Resources-You-Might-Have-Missed-74010.aspx

The 1s are because everything is perfectly correlated with itself, and the NAs are because there are NAs in your variables.

You will have to specify how you want R to compute the correlation when there are missing values, because the default is to only compute a coefficient with complete information.

You can change this behavior with the use argument to cor, see ?cor for details.

I used a few options mentioned above :

del self.left

or setting value to None using

self.left = None

It's important to know the differences and put a few exception handlers in place when you use set the value to None. If you're printing the value of the conditional statements using a template, say,

print("The value of the variable is {}".format(self.left))

you might see the value of the variable printing "The value of the variable is None". Thus, you'd have to put a few exception handlers there :

if self.left:
    #Then only print stuff

The above command will only print values if self.left is not None

I was able to trigger an SDK download like this:

1. Close Android Studio
2. Open android studio, but be ready
3. Once you see "loading project", click cancel. (this will only appear for seconds on a fast machine)
4. The SDK download window appeared!

Looking for EventHandling, ActionListener?

or code?

JButton b = new JButton("Clear");
b.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
        textfield.setText("");
        //textfield.setText(null); //or use this
    }
});

Also See
How to Use Buttons

This OTN-thread contains several ways to do string aggregation, including a performance comparison: http://forums.oracle.com/forums/message.jspa?messageID=1819487#1819487

JIT-Just in time the word itself says when it's needed (on demand)

Typical scenario:

The source code is completely converted into machine code

JIT scenario:

The source code will be converted into assembly language like structure [for ex IL (intermediate language) for C#, ByteCode for java].

The intermediate code is converted into machine language only when the application needs that is required codes are only converted to machine code.

JIT vs Non-JIT comparison:

• In JIT not all the code is converted into machine code first a part of the code that is necessary will be converted into machine code then if a method or functionality called is not in machine then that will be turned into machine code... it reduces burden on the CPU.

• As the machine code will be generated on run time....the JIT compiler will produce machine code that is optimised for running machine's CPU architecture.

JIT Examples:

1. In Java JIT is in JVM (Java Virtual Machine)
2. In C# it is in CLR (Common Language Runtime)
3. In Android it is in DVM (Dalvik Virtual Machine), or ART (Android RunTime) in newer versions.

You can use the Android app Barcode Scanner Terminal (DISCLAIMER! I'm the developer). It can scan the barcode and send it to the PC and in your case enter it on the web form. More details here.

Use this:

find . -type f -print0 | tar -czvf backup.tar.gz --null -T -

It will:

• deal with files with spaces, newlines, leading dashes, and other funniness
• handle an unlimited number of files
• won't repeatedly overwrite your backup.tar.gz like using tar -c with xargs will do when you have a large number of files

Also see:

• GNU tar manual
• How can I build a tar from stdin?, search for null

When you export you use the compatibility system set to MYSQL40. Worked for me.

I had an identical problem, which I solved by restarting my Python editor and shell. I had installed pywin32 but the new modules were not picked up until the restarts.

If you've already done that, do a search in your Python installation for win32api and you should find win32api.pyd under ${PYTHON_HOME}\Lib\site-packages\win32.

I also have the same problem. Turned out I have the @PropertySource annotation set on the main Application class to read a different base properties file, so the normal "application.properties" is not used anymore.

It makes it possible to bind member variables and functions in the uniform manner. The following is example with your Car class. More common usage would be binding std::pair::first and ::second when using in STL algorithms and Boost on a map.

#include <list>
#include <algorithm>
#include <iostream>
#include <iterator>
#include <boost/lambda/lambda.hpp>
#include <boost/lambda/bind.hpp>


class Car {
public:
    Car(int s): speed(s) {}
    void drive() {
        std::cout << "Driving at " << speed << " km/h" << std::endl;
    }
    int speed;
};

int main() {

    using namespace std;
    using namespace boost::lambda;

    list<Car> l;
    l.push_back(Car(10));
    l.push_back(Car(140));
    l.push_back(Car(130));
    l.push_back(Car(60));

    // Speeding cars
    list<Car> s;

    // Binding a value to a member variable.
    // Find all cars with speed over 60 km/h.
    remove_copy_if(l.begin(), l.end(),
                   back_inserter(s),
                   bind(&Car::speed, _1) <= 60);

    // Binding a value to a member function.
    // Call a function on each car.
    for_each(s.begin(), s.end(), bind(&Car::drive, _1));

    return 0;
}

I got the same error because I had accidentally used <div> instead of <canvas> as the element on which I attempt to call getContext.

__repr__ should return a printable representation of the object, most likely one of the ways possible to create this object. See official documentation here. __repr__ is more for developers while __str__ is for end users.

A simple example:

>>> class Point:
...   def __init__(self, x, y):
...     self.x, self.y = x, y
...   def __repr__(self):
...     return 'Point(x=%s, y=%s)' % (self.x, self.y)
>>> p = Point(1, 2)
>>> p
Point(x=1, y=2)

This is like passing a pointer to a pointer in C. In .NET this will allow you to change what the original T refers to, personally though I think if you are doing that in .NET you have probably got a design issue!

Using simple html,

 <div> 
    <object type="text/html" data="http://validator.w3.org/" width="800px" height="600px" style="overflow:auto;border:5px ridge blue">
    </object>
 </div>

Or jquery,

<script>
        $("#mydiv")
            .html('<object data="http://your-website-domain"/>');
</script>

JSFIDDLE DEMO

The accepted answer is good, but has two limitations.
It drops empty lines and lines beginning with ;

To read lines of any content, you need the delayed expansion toggling technic.

@echo off
SETLOCAL DisableDelayedExpansion
FOR /F "usebackq delims=" %%a in (`"findstr /n ^^ text.txt"`) do (
    set "var=%%a"
    SETLOCAL EnableDelayedExpansion
    set "var=!var:*:=!"
    echo(!var!
    ENDLOCAL
)

Findstr is used to prefix each line with the line number and a colon, so empty lines aren't empty anymore.

DelayedExpansion needs to be disabled, when accessing the %%a parameter, else exclamation marks ! and carets ^ will be lost, as they have special meanings in that mode.

But to remove the line number from the line, the delayed expansion needs to be enabled.
set "var=!var:*:=!" removes all up to the first colon (using delims=: would remove also all colons at the beginning of a line, not only the one from findstr).
The endlocal disables the delayed expansion again for the next line.

The only limitation is now the line length limit of ~8191, but there seems no way to overcome this.

You can use float on that particular div, e.g.

<div style="float:right;">

Float the div you want more space to have to the left as well:

<div style="float:left;">

If all else fails give the div on the right position:absolute and then move it as right as you want it to be.

<div style="position:absolute; left:-500px; top:30px;"> 

etc. Obviously put the style in a seperate stylesheet but this is just a quicker example.

This worked for me, as documented on this page:

TransformerFactory tf = TransformerFactory.newInstance();
Transformer trans = tf.newTransformer();
StringWriter sw = new StringWriter();
trans.transform(new DOMSource(document), new StreamResult(sw));
return sw.toString();

I know this is late to the game, but I wanted to share in case it helps someone.

Your exact situation may not apply, however I had a similar situation and setting the File attribute helped.

Try to set the File attribute to Normal:

var path = Server.MapPath("~/App_Data/file.txt");
File.SetAttributes(path, FileAttributes.Normal);
System.IO.File.WriteAllText(path, "Hello World");

I hope this helps someone.

There is an OFFSET as well that should do the trick:

SELECT column FROM table
LIMIT 10 OFFSET 10

@Mahender, you probably meant the difference between \W (instead of \w) and \b. If not, then I would agree with @BoltClock and @jwismar above. Otherwise continue reading.

\W would match any non-word character and so its easy to try to use it to match word boundaries. The problem is that it will not match the start or end of a line. \b is more suited for matching word boundaries as it will also match the start or end of a line. Roughly speaking (more experienced users can correct me here) \b can be thought of as (\W|^|$). [Edit: as @?mega mentions below, \b is a zero-length match so (\W|^|$) is not strictly correct, but hopefully helps explain the diff]

Quick example: For the string Hello World, .+\W would match Hello_ (with the space) but will not match World. .+\b would match both Hello and World.

You can create custom CSS tooltips using a data attribute, pseudo elements and content: attr() eg.

http://jsfiddle.net/clintioo/gLeydk0k/11/

<div data-tooltip="This is my tooltip">
    <label>Name</label>
    <input type="text" />
</div>

.

div:hover:before {
    content: attr(data-tooltip);
    position: absolute;
    padding: 5px 10px;
    margin: -3px 0 0 180px;
    background: orange;
    color: white;
    border-radius: 3px;
}

div:hover:after {
    content: '';
    position: absolute;
    margin: 6px 0 0 3px;
    width: 0;
    height: 0;
    border-top: 5px solid transparent;
    border-right: 10px solid orange;
    border-bottom: 5px solid transparent;
}

input[type="text"] {
    width: 125px;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}

I wouldn't use a Regex for this, but rather just split the string and check that the date is valid:

list($year, $month, $day, $hour, $minute, $second) = preg_split('%( |-|:)%', $mydatestring);
if(!checkdate($month, $day, $year)) {
     /* print error */
} 
/* check $hour, $minute and $second etc */

I think servlet is basically a java class which acts as a middle way between HTTP request and HTTP response.Servlet is also used to make your web page dynamic. Suppose for example if you want to redirect to another web page on server then you have to use servlets. Another important thing is that servlet can run on localhost as well as a web browser.

Like this:

Dim rng as Range
Set rng = ActiveCell.Resize(numRows, numCols)

then read the contents of that range to an array:

Dim arr As Variant
arr = rng.Value
'arr is now a two-dimensional array of size (numRows, numCols)

or, select the range (I don't think that's what you really want, but you ask for this in the question).

rng.Select

The !important rule is a way to make your CSS cascade but also have the rules you feel are most crucial always be applied. A rule that has the !important property will always be applied no matter where that rule appears in the CSS document.

So, if you have the following:

.class {
   color: red !important;
}
.outerClass .class {
   color: blue;
}

the rule with the important will be the one applied (not counting specificity)

I believe !important appeared in CSS1 so every browser supports it (IE4 to IE6 with a partial implementation, IE7+ full)

Also, it's something that you don't want to use pretty often, because if you're working with other people you can override other properties.

No IEnumerable is an interface, you can't create instance of interface

you can do something like this

IEnumerable<object> a = new object[0];

The below method to migrate my GIT Stash to GitLab by maintaining all branches and preserving history.

Clone the old repository to local.

git clone --bare <STASH-URL>

Create an empty repository in GitLab.

git push --mirror <GitLab-URL>

The above I performed when we migrated our code from stash to GitLab and it worked very well.

For Angular 8

Install npm-check-updates package

Run:

$ npm i npm-check-updates
$ ncu -u
$ npm install

This package will update all packages and resolve this issue

Notice: After update If you face this issue:

ERROR in The Angular Compiler requires TypeScript >=3.4.0 and <3.6.0 but 3.6.3 was found instead.

then run:

$ npm install [email protected]

Source Link

Open chrome browser. right click anywhere on a page > inspect elements > go to network tab > drag and drop the .har file You should see the logs.

calling bean action from a will be a good idea,keep attribute autoRun="true" example below

<p:remoteCommand autoRun="true" name="myRemoteCommand" action="#{bean.action}" partialSubmit="true" update=":form" />

You need to have Visual Studio's bin dir in your path. Pip install is trying to compile some C code.

SELECT
  category,
  COUNT(*) AS `num`
FROM
  posts
GROUP BY
  category

For the question

How can i run a jar file in command prompt but with arguments

.

To pass arguments to the jar file at the time of execution

java -jar myjar.jar arg1 arg2

In the main() method of "Main-Class" [mentioned in the manifest.mft file]of your JAR file. you can retrieve them like this:

String arg1 = args[0];
String arg2 = args[1];

If you're using Google Maps v2, call checkResize() on your map after resizing the container. link

UPDATE

Google Maps JavaScript API v2 was deprecated in 2011. It is not available anymore.

You could also have a union of the blank select with the select that has content:

select '' value, '' name
union
select value, name from mytable

In my case I got a trouble with the maxSize annotation in the entity, so I increased it from 2048 to 20048.

 /**
 * @Assert\File(
 *     maxSize = "20048k",
 *     mimeTypes = {"application/pdf", "application/x-pdf"},
 *     mimeTypesMessage = "Please upload a valid PDF"
 * )
 */
private $file;

hope this answer helps!

flash message after redirect will available in controller not in view. to show in view get in controller's action and pass it view

final Class B{

    static $staticVar;
    static function getA(){
        self::$staticVar = New A;
    }
}

the stucture of b is calld a singeton handler you can also do it in a

Class a{
    static $instance;
    static function getA(...){
        if(!isset(self::$staticVar)){
            self::$staticVar = New A(...);
        }
        return self::$staticVar;
    }
}

this is the singleton use $a = a::getA(...);

I think this code will help you:

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net.Mail;

public partial class _Default : System.Web.UI.Page
{
  protected void Page_Load(object sender, EventArgs e)
  {

  }

  protected void btnSubmit_Click(object sender, EventArgs e)
  {
    try
    {
      MailAddress SendFrom = new MailAddress(txtFrom.Text);
      MailAddress SendTo = new MailAddress(txtTo.Text);

      MailMessage MyMessage = new MailMessage(SendFrom, SendTo);

      MyMessage.Subject = txtSubject.Text;
      MyMessage.Body = txtBody.Text;

      Attachment attachFile = new Attachment(txtAttachmentPath.Text);
      MyMessage.Attachments.Add(attachFile);

      SmtpClient emailClient = new SmtpClient(txtSMTPServer.Text);
      emailClient.Send(MyMessage);

      litStatus.Text = "Message Sent";
    }
    catch (Exception ex)
    {
      litStatus.Text = ex.ToString();
    }
  }
}

If the string was constructed in the same program, I would recommend using this:

String newline = System.getProperty("line.separator");
boolean hasNewline = word.contains(newline);

But if you are specced to use \n, this driver illustrates what to do:

class NewLineTest {
    public static void main(String[] args) {
        String hasNewline = "this has a newline\n.";
        String noNewline = "this doesn't";

        System.out.println(hasNewline.contains("\n"));
        System.out.println(hasNewline.contains("\\n"));
        System.out.println(noNewline.contains("\n"));
        System.out.println(noNewline.contains("\\n"));

    }

}

Resulted in

true
false
false
false

In reponse to your comment:

class NewLineTest {
    public static void main(String[] args) {
        String word = "test\n.";
        System.out.println(word.length());
        System.out.println(word);
        word = word.replace("\n","\n ");
        System.out.println(word.length());
        System.out.println(word);

    }

}

Results in

6
test
.
7
test
 .

Maybe you are using:

$(document).ready(function(){
   // Your code here
 });

Try this instead:

window.onload = function(){  }

'\r' = carriage return and '\n' = line feed.

In fact, there are some different behaviors when you use them in different OSes. On Unix it is '\n', but it is '\r''\n' on Windows.

If you are using a Form Control, you can get the same property as ActiveX by using OLEFormat.Object property of the Shape Object. Better yet assign it in a variable declared as OptionButton to get the Intellisense kick in.

Dim opt As OptionButton

With Sheets("Sheet1") ' Try to be always explicit
    Set opt = .Shapes("Option Button 1").OLEFormat.Object ' Form Control
    Debug.Pring opt.Value ' returns 1 (true) or -4146 (false)
End With

But then again, you really don't need to know the value.
If you use Form Control, you associate a Macro or sub routine with it which is executed when it is selected. So you just need to set up a sub routine that identifies which button is clicked and then execute a corresponding action for it.

For example you have 2 Form Control Option Buttons.

Sub CheckOptions()
    Select Case Application.Caller
    Case "Option Button 1"
    ' Action for option button 1
    Case "Option Button 2"
    ' Action for option button 2
    End Select
End Sub

In above code, you have only one sub routine assigned to both option buttons.
Then you test which called the sub routine by checking Application.Caller.
This way, no need to check whether the option button value is true or false.

I realize this is an old post but as I just ran into the same issue and had trouble finding the answer I thought I'd add a bit.

So @hammar's answer is correct. Using push.default simple is, in a way, like configuring tracking on your branches so you don't need to specify remotes and branches when pushing and pulling. The matching option will push all branches to their corresponding counterparts on the default remote (which is the first one that was set up unless you've configured your repo otherwise).

One thing I hope others find useful in the future is that I was running Git 1.8 on OS X Mountain Lion and never saw this error. Upgrading to Mavericks is what suddenly made it show up (running git --version will show git version 1.8.3.4 (Apple Git-47) which I'd never seen until the update to the OS.

Tables work differently; sometimes counter-intuitively.

The solution is to use width on the table cells instead of max-width.

Although it may sound like in that case the cells won't shrink below the given width, they will actually.
with no restrictions on c, if you give the table a width of 70px, the widths of a, b and c will come out as 16, 42 and 12 pixels, respectively.
With a table width of 400 pixels, they behave like you say you expect in your grid above.
Only when you try to give the table too small a size (smaller than a.min+b.min+the content of C) will it fail: then the table itself will be wider than specified.

I made a snippet based on your fiddle, in which I removed all the borders and paddings and border-spacing, so you can measure the widths more accurately.

table {_x000D_
  width: 70px;_x000D_
}_x000D_
_x000D_
table, tbody, tr, td {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
  border: 0;_x000D_
  border-spacing: 0;_x000D_
}_x000D_
_x000D_
.a, .c {_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.b {_x000D_
  background-color: #F77;_x000D_
}_x000D_
_x000D_
.a {_x000D_
  min-width: 10px;_x000D_
  width: 20px;_x000D_
  max-width: 20px;_x000D_
}_x000D_
_x000D_
.b {_x000D_
  min-width: 40px;_x000D_
  width: 45px;_x000D_
  max-width: 45px;_x000D_
}_x000D_
_x000D_
.c {}

<table>_x000D_
  <tr>_x000D_
    <td class="a">A</td>_x000D_
    <td class="b">B</td>_x000D_
    <td class="c">C</td>_x000D_
  </tr>_x000D_
</table>

See here if you want to grant a Facebook App permanent access to a page (even when you / the app owner are logged out):

http://developers.facebook.com/docs/opengraph/using-app-tokens/

"An App Access Token does not expire unless you refresh the application secret through your app settings."

Log in as root, then run the following MySQL commands:

GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost';
FLUSH PRIVILEGES;

You can use array_agg function for that:

SELECT "Movie",
array_to_string(array_agg(distinct "Actor"),',') AS Actor
FROM Table1
GROUP BY "Movie";

Result:

See this SQLFiddle

For more See 9.18. Aggregate Functions

Use this regex (?<!\\)' for searching an unescaped apostrophe. It finds an apostrophe that not preceded by a backslash.

A bit late to the game...but here's a quite comprehensive post I wrote a few months back, detailing the major differences between MYISAM and InnoDB. Grab a cuppa (and maybe a biscuit), and enjoy.

The major difference between MyISAM and InnoDB is in referential integrity and transactions. There are also other difference such as locking, rollbacks, and full-text searches.

Referential Integrity

Referential integrity ensures that relationships between tables remains consistent. More specifically, this means when a table (e.g. Listings) has a foreign key (e.g. Product ID) pointing to a different table (e.g. Products), when updates or deletes occur to the pointed-to table, these changes are cascaded to the linking table. In our example, if a product is renamed, the linking table’s foreign keys will also update; if a product is deleted from the ‘Products’ table, any listings which point to the deleted entry will also be deleted. Furthermore, any new listing must have that foreign key pointing to a valid, existing entry.

InnoDB is a relational DBMS (RDBMS) and thus has referential integrity, while MyISAM does not.

Transactions & Atomicity

Data in a table is managed using Data Manipulation Language (DML) statements, such as SELECT, INSERT, UPDATE and DELETE. A transaction group two or more DML statements together into a single unit of work, so either the entire unit is applied, or none of it is.

MyISAM do not support transactions whereas InnoDB does.

If an operation is interrupted while using a MyISAM table, the operation is aborted immediately, and the rows (or even data within each row) that are affected remains affected, even if the operation did not go to completion.

If an operation is interrupted while using an InnoDB table, because it using transactions, which has atomicity, any transaction which did not go to completion will not take effect, since no commit is made.

Table-locking vs Row-locking

When a query runs against a MyISAM table, the entire table in which it is querying will be locked. This means subsequent queries will only be executed after the current one is finished. If you are reading a large table, and/or there are frequent read and write operations, this can mean a huge backlog of queries.

When a query runs against an InnoDB table, only the row(s) which are involved are locked, the rest of the table remains available for CRUD operations. This means queries can run simultaneously on the same table, provided they do not use the same row.

This feature in InnoDB is known as concurrency. As great as concurrency is, there is a major drawback that applies to a select range of tables, in that there is an overhead in switching between kernel threads, and you should set a limit on the kernel threads to prevent the server coming to a halt.

Transactions & Rollbacks

When you run an operation in MyISAM, the changes are set; in InnoDB, those changes can be rolled back. The most common commands used to control transactions are COMMIT, ROLLBACK and SAVEPOINT. 1. COMMIT - you can write multiple DML operations, but the changes will only be saved when a COMMIT is made 2. ROLLBACK - you can discard any operations that have not yet been committed yet 3. SAVEPOINT - sets a point in the list of operations to which a ROLLBACK operation can rollback to

Reliability

MyISAM offers no data integrity - Hardware failures, unclean shutdowns and canceled operations can cause the data to become corrupt. This would require full repair or rebuilds of the indexes and tables.

InnoDB, on the other hand, uses a transactional log, a double-write buffer and automatic checksumming and validation to prevent corruption. Before InnoDB makes any changes, it records the data before the transactions into a system tablespace file called ibdata1. If there is a crash, InnoDB would autorecover through the replay of those logs.

FULLTEXT Indexing

InnoDB does not support FULLTEXT indexing until MySQL version 5.6.4. As of the writing of this post, many shared hosting providers’ MySQL version is still below 5.6.4, which means FULLTEXT indexing is not supported for InnoDB tables.

However, this is not a valid reason to use MyISAM. It’s best to change to a hosting provider that supports up-to-date versions of MySQL. Not that a MyISAM table that uses FULLTEXT indexing cannot be converted to an InnoDB table.

Conclusion

In conclusion, InnoDB should be your default storage engine of choice. Choose MyISAM or other data types when they serve a specific need.

If you're not sure whether the object has been disposed or not, you should call the Dispose method itself rather than methods such as Close. While the framework doesn't guarantee that the Dispose method must run without exceptions even if the object had previously been disposed, it's a common pattern and to my knowledge implemented on all disposable objects in the framework.

The typical pattern for Dispose, as per Microsoft:

public void Dispose() 
{
    Dispose(true);

    // Use SupressFinalize in case a subclass
    // of this type implements a finalizer.
    GC.SuppressFinalize(this);      
}

protected virtual void Dispose(bool disposing)
{
    // If you need thread safety, use a lock around these 
    // operations, as well as in your methods that use the resource.
    if (!_disposed)
    {
        if (disposing) {
            if (_resource != null)
                _resource.Dispose();
                Console.WriteLine("Object disposed.");
        }

        // Indicate that the instance has been disposed.
        _resource = null;
        _disposed = true;   
    }
}

Notice the check on _disposed. If you were to call a Dispose method implementing this pattern, you could call Dispose as many times as you wanted without hitting exceptions.

I think you need something a bit more generic. Try this:

public static System.Boolean IsNumeric (System.Object Expression)
{
    if(Expression == null || Expression is DateTime)
        return false;

    if(Expression is Int16 || Expression is Int32 || Expression is Int64 || Expression is Decimal || Expression is Single || Expression is Double || Expression is Boolean)
        return true;

    try 
    {
        if(Expression is string)
            Double.Parse(Expression as string);
        else
            Double.Parse(Expression.ToString());
            return true;
        } catch {} // just dismiss errors but return false
        return false;
    }
}

Hope it helps!

just go to add reference then add

system.net.http

The initialize method is called after all @FXML annotated members have been injected. Suppose you have a table view you want to populate with data:

class MyController { 
    @FXML
    TableView<MyModel> tableView; 

    public MyController() {
        tableView.getItems().addAll(getDataFromSource()); // results in NullPointerException, as tableView is null at this point. 
    }

    @FXML
    public void initialize() {
        tableView.getItems().addAll(getDataFromSource()); // Perfectly Ok here, as FXMLLoader already populated all @FXML annotated members. 
    }
}

a vue3 replacement of this answer:

// Vue3

const app = Vue.createApp({})
app.config.globalProperties.$hostname = 'http://localhost:3000'


app.component('a-child-component', {
  mounted() {
    console.log(this.$hostname) // 'http://localhost:3000'
  }
})

"echo off" is not ignored. "echo off" means that you do not want the commands echoed, it does not say anything about the errors produced by the commands.

The lines you showed us look okay, so the problem is probably not there. So, please show us more lines. Also, please show us the exact value of INSTALL_PATH.

Comparing the MSDN articles "What's New in the C# 2.0 Language and Compiler" and "What's New in Visual C# 2005", it is possible to deduce that "C# major_version.minor_version" is coined according to the compiler's version numbering.

There is C# 1.2 corresponding to .NET 1.1 and VS 2003 and also named as Visual C# .NET 2003.

But further on Microsoft stopped to increment the minor version (after the dot) numbers or to have them other than zero, 0. Though it should be noted that C# corresponding to .NET 3.5 is named in msdn.microsoft.com as "Visual C# 2008 Service Pack 1".

There are two parallel namings: By major .NET/compiler version numbering and by Visual Studio numbering.

C# 2.0 is a synonym for Visual C# 2005

C# 3.0 corresponds (or, more correctly, can target) to:

• .NET 2.0 <==> Visual C# 2005
• .NET3.0 <==> Visual C# 2008
• .NET 3.5 <==> Visual C# 2008 Service Pack 1

Before creating a new branch always the best practice is to have the latest of repo in your local machine. Follow these steps for error free branch creation.

 1. $ git branch (check which branches exist and which one is currently active (prefixed with *). This helps you avoid creating duplicate/confusing branch name)
 2. $ git branch <new_branch> (creates new branch)
 3. $ git checkout new_branch
 4. $ git add . (After making changes in the current branch)
 5. $ git commit -m "type commit msg here"
 6. $ git checkout master (switch to master branch so that merging with new_branch can be done)
 7. $ git merge new_branch (starts merging)
 8. $ git push origin master (push to the remote server)

I referred this blog and I found it to be a cleaner approach.

You can use res.render() or res.redirect() method to redirect to another page using node.js express

Eg:

var bodyParser = require('body-parser');
var express = require('express');
var navigator = require('web-midi-api');
var app = express();

app.use(express.static(__dirname + '/'));
app.use(bodyParser.urlencoded({extend:true}));
app.engine('html', require('ejs').renderFile);
app.set('view engine', 'html');
app.set('views', __dirname);

app.get('/', function(req, res){
    res.render("index");
});

//This reponds a post request for the login page
app.post('/login', function (req, res) {
    console.log("Got a POST request for the login");
    var data = {
        "email": req.body.email,
        "password": req.body.password
    };

    console.log(data);

    //Data insertion code
    var MongoClient = require('mongodb').MongoClient;
    var url = "mongodb://localhost:27017/";

    MongoClient.connect(url, function(err, db) {
        if (err) throw err;
        var dbo = db.db("college");
        var query = { email: data.email };
        dbo.collection("user").find(query).toArray(function(err, result) {
            if (err) throw err;
            console.log(result);
            if(result[0].password == data.password)


 res.redirect('dashboard.html');
            else


 res.redirect('login-error.html');
            db.close();
        });
    });

});


// This responds a POST request for the add user
app.post('/insert', function (req, res) {
    console.log("Got a POST request for the add user");

    var data = {
        "first_name" : req.body.firstName,
        "second_name" : req.body.secondName,
        "organization" : req.body.organization,
        "email": req.body.email,
        "mobile" : req.body.mobile,
    };

    console.log(data);

    **res.render('success.html',{email:data.email,password:data.password});**

});


//make sure that Service Workers are supported.
if (navigator.serviceWorker) {
    navigator.serviceWorker.register('service-worker.js', {scope: '/'})
        .then(function (registration) {
            console.log(registration);
        })
        .catch(function (e) {
            console.error(e);
        })
} else {
    console.log('Service Worker is not supported in this browser.');
}


// TODO add service worker code here
if ('serviceWorker' in navigator) {
    navigator.serviceWorker
        .register('service-worker.js')
        .then(function() { console.log('Service Worker Registered'); });
}

var server = app.listen(63342, function () {

    var host = server.address().host;
    var port = server.address().port;

    console.log("Example app listening at http://localhost:%s", port)
});

Here in the login section, If the email and password matches in the database then the site is directed to dashbaord.html otherwise we will show page-error.html using res.redirect() method. Also you can use res.render() to render a page in node.js

dates_dict[key] = dates_dict.get(key, []).append(date) sets dates_dict[key] to None as list.append returns None.

In [5]: l = [1,2,3]

In [6]: var = l.append(3)

In [7]: print var
None

You should use collections.defaultdict

import collections
dates_dict = collections.defaultdict(list)

Shelving is a way of saving all of the changes on your box without checking in. The changes are persisted on the server. At any later time you or any of your team-mates can "unshelve" them back onto any one of your machines.

It's also great for review purposes. On my team for a check in we shelve up our changes and send out an email with the change description and name of the changeset. People on the team can then view the changeset and give feedback.

FYI: The best way to review a shelveset is with the following command

tfpt review /shelveset:shelvesetName;userName

tfpt is a part of the Team Foundation Power Tools

My c++ STL code to initialise 5*3 2-D vector with zero

#include <iostream>
using namespace std;
#include <vector>
int main()
{// if we wnt to initialise a 2 D vector with 0;

    vector<vector<int>> v1(5, vector<int>(3,0));

    for(int i=0;i<v1.size();i++) 
{
        for(int j=0;j<v1[i].size();j++)

           cout<<v1[i][j]<<" ";

            cout<<endl;
    }
}

XAMPP for linux and mac comes with ProFTPD. Make sure to start the service from XAMPP control panel -> manage servers.

Further complete instructions can be found at localhost XAMPP dashboard -> How-to guides -> Configure FTP Access. I have pasted them below :

1. Open a new Linux terminal and ensure you are logged in as root.

2. Create a new group named ftp. This group will contain those user accounts allowed to upload files via FTP.

groupadd ftp

3. Add your account (in this example, susan) to the new group. Add other users if needed.

usermod -a -G ftp susan

4. Change the ownership and permissions of the htdocs/ subdirectory of the XAMPP installation directory (typically, /opt/lampp) so that it is writable by the the new ftp group.

cd /opt/lampp chown root.ftp htdocs chmod 775 htdocs

5. Ensure that proFTPD is running in the XAMPP control panel.

You can now transfer files to the XAMPP server using the steps below:

1. Start an FTP client like winSCP or FileZilla and enter connection details as below.

If you’re connecting to the server from the same system, use "127.0.0.1" as the host address. If you’re connecting from a different system, use the network hostname or IP address of the XAMPP server.

Use "21" as the port.

Enter your Linux username and password as your FTP credentials.

Your FTP client should now connect to the server and enter the /opt/lampp/htdocs/ directory, which is the default Web server document root.

2. Transfer the file from your home directory to the server using normal FTP transfer conventions. If you’re using a graphical FTP client, you can usually drag and drop the file from one directory to the other. If you’re using a command-line FTP client, you can use the FTP PUT command.

Once the file is successfully transferred, you should be able to see it in action.

npm install package_x --save

The given package (package_x) will be saved in package.json inside dependencies. if you add

npm install <<package_x>> --save-dev

then it will be saved inside devDependencies.