Programs & Examples On #Hp exstream

What is the difference between private and protected members of C++ classes?

  • Private: It is an access specifier. By default the instance (member) variables or the methods of a class in c++/java are private. During inheritance, the code and the data are always inherited but is not accessible outside the class. We can declare our data members as private so that no one can make direct changes to our member variables and we can provide public getters and setters in order to change our private members. And this concept is always applied in the business rule.

  • Protected: It is also an access specifier. In C++, the protected members are accessible within the class and to the inherited class but not outside the class. In Java, the protected members are accessible within the class, to the inherited class as well as to all the classes within the same package.

Why both no-cache and no-store should be used in HTTP response?

For chrome, no-cache is used to reload the page on a re-visit, but it still caches it if you go back in history (back button). To reload the page for history-back as well, use no-store. IE needs must-revalidate to work in all occasions.

So just to be sure to avoid all bugs and misinterpretations I always use

Cache-Control: no-store, no-cache, must-revalidate

if I want to make sure it reloads.

Adding 30 minutes to time formatted as H:i in PHP

$time = 30 * 60; //30 minutes
$start_time = date('Y-m-d h:i:s', time() - $time);
$end_time = date('Y-m-d h:i:s', time() + $time);

How to find locked rows in Oracle

you can find the locked tables in oralce by querying with following query

    select
   c.owner,
   c.object_name,
   c.object_type,
   b.sid,
   b.serial#,
   b.status,
   b.osuser,
   b.machine
from
   v$locked_object a ,
   v$session b,
   dba_objects c
where
   b.sid = a.session_id
and
   a.object_id = c.object_id;

How to restore the menu bar in Visual Studio Code

Press Ctrl + Shift + P to open the Command Palette, then write command : Toggle Menu Bar

Read .csv file in C

Hopefully this would get you started

See it live on http://ideone.com/l23He (using stdin)

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

const char* getfield(char* line, int num)
{
    const char* tok;
    for (tok = strtok(line, ";");
            tok && *tok;
            tok = strtok(NULL, ";\n"))
    {
        if (!--num)
            return tok;
    }
    return NULL;
}

int main()
{
    FILE* stream = fopen("input", "r");

    char line[1024];
    while (fgets(line, 1024, stream))
    {
        char* tmp = strdup(line);
        printf("Field 3 would be %s\n", getfield(tmp, 3));
        // NOTE strtok clobbers tmp
        free(tmp);
    }
}

Output:

Field 3 would be nazwisko
Field 3 would be Kowalski
Field 3 would be Nowak

How to test for $null array in PowerShell

It's an array, so you're looking for Count to test for contents.

I'd recommend

$foo.count -gt 0

The "why" of this is related to how PSH handles comparison of collection objects

Why is using onClick() in HTML a bad practice?

Your question will trigger discussion I suppose. The general idea is that it's good to separate behavior and structure. Furthermore, afaik, an inline click handler has to be evalled to 'become' a real javascript function. And it's pretty old fashioned, allbeit that that's a pretty shaky argument. Ah, well, read some about it @quirksmode.org

How to redirect to another page using AngularJS?

You can redirect to a new URL in different ways.

  1. You can use $window which will also refresh the page
  2. You can "stay inside" the single page app and use $location in which case you can choose between $location.path(YOUR_URL); or $location.url(YOUR_URL);. So the basic difference between the 2 methods is that $location.url() also affects get parameters whilst $location.path() does not.

I would recommend reading the docs on $location and $window so you get a better grasp on the differences between them.

UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only

This is the normal behavior and the reason is that your sqlCommandHandlerService.persist method needs a TX when being executed (because it is marked with @Transactional annotation). But when it is called inside processNextRegistrationMessage, because there is a TX available, the container doesn't create a new one and uses existing TX. So if any exception occurs in sqlCommandHandlerService.persist method, it causes TX to be set to rollBackOnly (even if you catch the exception in the caller and ignore it).

To overcome this you can use propagation levels for transactions. Have a look at this to find out which propagation best suits your requirements.

Update; Read this!

Well after a colleague came to me with a couple of questions about a similar situation, I feel this needs a bit of clarification.
Although propagations solve such issues, you should be VERY careful about using them and do not use them unless you ABSOLUTELY understand what they mean and how they work. You may end up persisting some data and rolling back some others where you don't expect them to work that way and things can go horribly wrong.


EDIT Link to current version of the documentation

Terminating idle mysql connections

I don't see any problem, unless you are not managing them using a connection pool.

If you use connection pool, these connections are re-used instead of initiating new connections. so basically, leaving open connections and re-use them it is less problematic than re-creating them each time.

How to convert Json array to list of objects in c#

As others have already pointed out, the reason you are not getting the results you expect is because your JSON does not match the class structure that you are trying to deserialize into. You either need to change your JSON or change your classes. Since others have already shown how to change the JSON, I will take the opposite approach here.

To match the JSON you posted in your question, your classes should be defined like those below. Notice I've made the following changes:

  1. I added a Wrapper class corresponding to the outer object in your JSON.
  2. I changed the Values property of the ValueSet class from a List<Value> to a Dictionary<string, Value> since the values property in your JSON contains an object, not an array.
  3. I added some additional [JsonProperty] attributes to match the property names in your JSON objects.

Class definitions:

class Wrapper
{
    [JsonProperty("JsonValues")]
    public ValueSet ValueSet { get; set; }
}

class ValueSet
{
    [JsonProperty("id")]
    public string Id { get; set; }
    [JsonProperty("values")]
    public Dictionary<string, Value> Values { get; set; }
}

class Value
{
    [JsonProperty("id")]
    public string Id { get; set; }
    [JsonProperty("diaplayName")]
    public string DisplayName { get; set; }
}

You need to deserialize into the Wrapper class, not the ValueSet class. You can then get the ValueSet from the Wrapper.

var valueSet = JsonConvert.DeserializeObject<Wrapper>(jsonString).ValueSet;

Here is a working program to demonstrate:

class Program
{
    static void Main(string[] args)
    {
        string jsonString = @"
        {
            ""JsonValues"": {
                ""id"": ""MyID"",
                ""values"": {
                    ""value1"": {
                        ""id"": ""100"",
                        ""diaplayName"": ""MyValue1""
                    },
                    ""value2"": {
                        ""id"": ""200"",
                        ""diaplayName"": ""MyValue2""
                    }
                }
            }
        }";

        var valueSet = JsonConvert.DeserializeObject<Wrapper>(jsonString).ValueSet;

        Console.WriteLine("id: " + valueSet.Id);
        foreach (KeyValuePair<string, Value> kvp in valueSet.Values)
        {
            Console.WriteLine(kvp.Key + " id: " + kvp.Value.Id);
            Console.WriteLine(kvp.Key + " name: " + kvp.Value.DisplayName);
        }
    }
}

And here is the output:

id: MyID
value1 id: 100
value1 name: MyValue1
value2 id: 200
value2 name: MyValue2

How do you get a timestamp in JavaScript?

I highly recommend using moment.js. To get the number of milliseconds since UNIX epoch, do

moment().valueOf()

To get the number of seconds since UNIX epoch, do

moment().unix()

You can also convert times like so:

moment('2015-07-12 14:59:23', 'YYYY-MM-DD HH:mm:ss').valueOf()

I do that all the time. No pun intended.

To use moment.js in the browser:

<script src="moment.js"></script>
<script>
    moment().valueOf();
</script>

For more details, including other ways of installing and using MomentJS, see their docs

How to write to the Output window in Visual Studio?

Use OutputDebugString instead of afxDump.

Example:

#define _TRACE_MAXLEN 500

#if _MSC_VER >= 1900
#define _PRINT_DEBUG_STRING(text) OutputDebugString(text)
#else // _MSC_VER >= 1900
#define _PRINT_DEBUG_STRING(text) afxDump << text
#endif // _MSC_VER >= 1900

void MyTrace(LPCTSTR sFormat, ...)
{
    TCHAR text[_TRACE_MAXLEN + 1];
    memset(text, 0, _TRACE_MAXLEN + 1);
    va_list args;
    va_start(args, sFormat);
    int n = _vsntprintf(text, _TRACE_MAXLEN, sFormat, args);
    va_end(args);
    _PRINT_DEBUG_STRING(text);
    if(n <= 0)
        _PRINT_DEBUG_STRING(_T("[...]"));
}

How to return multiple values in one column (T-SQL)?

Well... I see that an answer was already accepted... but I think you should see another solutions anyway:

/* EXAMPLE */
DECLARE @UserAliases TABLE(UserId INT , Alias VARCHAR(10))
INSERT INTO @UserAliases (UserId,Alias) SELECT 1,'MrX'
     UNION ALL SELECT 1,'MrY' UNION ALL SELECT 1,'MrA'
     UNION ALL SELECT 2,'Abc' UNION ALL SELECT 2,'Xyz'

/* QUERY */
;WITH tmp AS ( SELECT DISTINCT UserId FROM @UserAliases )
SELECT 
    LEFT(tmp.UserId, 10) +
    '/ ' +
    STUFF(
            (   SELECT ', '+Alias 
                FROM @UserAliases 
                WHERE UserId = tmp.UserId 
                FOR XML PATH('') 
            ) 
            , 1, 2, ''
        ) AS [UserId/Alias]
FROM tmp

/* -- OUTPUT
  UserId/Alias
  1/ MrX, MrY, MrA
  2/ Abc, Xyz    
*/

Regex pattern for checking if a string starts with a certain substring?

I really recommend using the String.StartsWith method over the Regex.IsMatch if you only plan to check the beginning of a string.

  • Firstly, the regular expression in C# is a language in a language with does not help understanding and code maintenance. Regular expression is a kind of DSL.
  • Secondly, many developers does not understand regular expressions: it is something which is not understandable for many humans.
  • Thirdly, the StartsWith method brings you features to enable culture dependant comparison which regular expressions are not aware of.

In your case you should use regular expressions only if you plan implementing more complex string comparison in the future.

Is there a standardized method to swap two variables in Python?

To get around the problems explained by eyquem, you could use the copy module to return a tuple containing (reversed) copies of the values, via a function:

from copy import copy

def swapper(x, y):
  return (copy(y), copy(x))

Same function as a lambda:

swapper = lambda x, y: (copy(y), copy(x))

Then, assign those to the desired names, like this:

x, y = swapper(y, x)

NOTE: if you wanted to you could import/use deepcopy instead of copy.

When to use MongoDB or other document oriented database systems?

Note that Mongo essentially stores JSON. If your app is dealing with a lot of JS Objects (with nesting) and you want to persist these objects then there is a very strong argument for using Mongo. It makes your DAL and MVC layers ultra thin, because they are not un-packaging all the JS object properties and trying to force-fit them into a structure (schema) that they don't naturally fit into.

We have a system that has several complex JS Objects at its heart, and we love Mongo because we can persist everything really, really easily. Our objects are also rather amorphous and unstructured, and Mongo soaks up that complication without blinking. We have a custom reporting layer that deciphers the amorphous data for human consumption, and that wasn't that difficult to develop.

What is tail recursion?

In traditional recursion, the typical model is that you perform your recursive calls first, and then you take the return value of the recursive call and calculate the result. In this manner, you don't get the result of your calculation until you have returned from every recursive call.

In tail recursion, you perform your calculations first, and then you execute the recursive call, passing the results of your current step to the next recursive step. This results in the last statement being in the form of (return (recursive-function params)). Basically, the return value of any given recursive step is the same as the return value of the next recursive call.

The consequence of this is that once you are ready to perform your next recursive step, you don't need the current stack frame any more. This allows for some optimization. In fact, with an appropriately written compiler, you should never have a stack overflow snicker with a tail recursive call. Simply reuse the current stack frame for the next recursive step. I'm pretty sure Lisp does this.

What is process.env.PORT in Node.js?

  • if you run node index.js ,Node will use 3000

  • If you run PORT=4444 node index.js, Node will use process.env.PORT which equals to 4444 in this example. Run with sudo for ports below 1024.

Accessing Websites through a Different Port?

No, as the server decides what port it is run on. Perhaps you could install a proxy, which would redirect the port, but in the end the connection would be made on port 80 from your machine.

How do you wait for input on the same Console.WriteLine() line?

As Matt has said, use Console.Write. I would also recommend explicitly flushing the output, however - I believe WriteLine does this automatically, but I'd seen oddities when just using Console.Write and then waiting. So Matt's code becomes:

Console.Write("What is your name? ");
Console.Out.Flush();
var name = Console.ReadLine();

@JsonProperty annotation on field as well as getter/setter

In addition to existing good answers, note that Jackson 1.9 improved handling by adding "property unification", meaning that ALL annotations from difference parts of a logical property are combined, using (hopefully) intuitive precedence.

In Jackson 1.8 and prior, only field and getter annotations were used when determining what and how to serialize (writing JSON); and only and setter annotations for deserialization (reading JSON). This sometimes required addition of "extra" annotations, like annotating both getter and setter.

With Jackson 1.9 and above these extra annotations are NOT needed. It is still possible to add those; and if different names are used, one can create "split" properties (serializing using one name, deserializing using other): this is occasionally useful for sort of renaming.

tooltips for Button

Simply add a title to your button.

_x000D_
_x000D_
<button title="Hello World!">Sample Button</button>
_x000D_
_x000D_
_x000D_

How do I resolve ClassNotFoundException?

Try these if you use maven. I use maven for my project and when I do mvn clean install and try to run a program it throws the exception. So, I clean the project and run it again and it works for me.

I use eclipse IDE.

For Class Not Found Exception when running Junit test, try running mvn clean test once. It will compile all the test classes.

Updating a java map entry

You just use the method

public Object put(Object key, Object value)

if the key was already present in the Map then the previous value is returned.

What does 'corrupted double-linked list' mean

I ran into this error in some code where someone was calling exit() in one thread about the same time as main() returned, so all the global/static constructors were being kicked off in two separate threads simultaneously.

This error also manifests as double free or corruption, or a segfault/sig11 inside exit() or inside malloc_consolidate, and likely others. The call stack for the malloc_consolidate crash may resemble:

#0  0xabcdabcd in malloc_consolidate () from /lib/libc.so.6
#1  0xabcdabcd in _int_free () from /lib/libc.so.6
#2  0xabcdabcd in operator delete (...)
#3  0xabcdabcd in operator delete[] (...)
(...)

I couldn't get it to exhibit this problem while running under valgrind.

jQuery UI " $("#datepicker").datepicker is not a function"

I just ran into a similar issue. When I changed my script reference from self-closing tags (ie, <script src=".." />) to empty nodes (ie, <script src=".."></script>) my errors went away and I could suddenly reference the jQuery UI functions.

At the time, I didn't realize this was just a brain-fart of me not closing it properly to begin with. (I'm posting this simply on the chance that anyone else coming across the thread is having a similar issue.)

adding x and y axis labels in ggplot2

[Note: edited to modernize ggplot syntax]

Your example is not reproducible since there is no ex1221new (there is an ex1221 in Sleuth2, so I guess that is what you meant). Also, you don't need (and shouldn't) pull columns out to send to ggplot. One advantage is that ggplot works with data.frames directly.

You can set the labels with xlab() and ylab(), or make it part of the scale_*.* call.

library("Sleuth2")
library("ggplot2")
ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area() + 
  xlab("My x label") +
  ylab("My y label") +
  ggtitle("Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

enter image description here

ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area("Nitrogen") + 
  scale_x_continuous("My x label") +
  scale_y_continuous("My y label") +
  ggtitle("Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

enter image description here

An alternate way to specify just labels (handy if you are not changing any other aspects of the scales) is using the labs function

ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area() + 
  labs(size= "Nitrogen",
       x = "My x label",
       y = "My y label",
       title = "Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

which gives an identical figure to the one above.

ASP.Net MVC - Read File from HttpPostedFileBase without save

A slight change to Thangamani Palanisamy answer, which allows the Binary reader to be disposed and corrects the input length issue in his comments.

string result = string.Empty;

using (BinaryReader b = new BinaryReader(file.InputStream))
{
  byte[] binData = b.ReadBytes(file.ContentLength);
  result = System.Text.Encoding.UTF8.GetString(binData);
}

How to remove an element from an array in Swift

If you have array of custom Objects, you can search by specific property like this:

if let index = doctorsInArea.firstIndex(where: {$0.id == doctor.id}){
    doctorsInArea.remove(at: index)
}

or if you want to search by name for example

if let index = doctorsInArea.firstIndex(where: {$0.name == doctor.name}){
    doctorsInArea.remove(at: index)
}

Message 'src refspec master does not match any' when pushing commits in Git

I was getting this error because my local branchname did not match the new remote branch I was trying to create with git push origin <<branchname>>.

How to check if a string starts with "_" in PHP?

Since someone mentioned efficiency, I've benchmarked the functions given so far out of curiosity:

function startsWith1($str, $char) {
    return strpos($str, $char) === 0;
}
function startsWith2($str, $char) {
    return stripos($str, $char) === 0;
}
function startsWith3($str, $char) {
    return substr($str, 0, 1) === $char;
}
function startsWith4($str, $char){
    return $str[0] === $char;
}
function startsWith5($str, $char){
    return (bool) preg_match('/^' . $char . '/', $str);
}
function startsWith6($str, $char) {
    if (is_null($encoding)) $encoding = mb_internal_encoding();
    return mb_substr($str, 0, mb_strlen($char, $encoding), $encoding) === $char;
}

Here are the results on my average DualCore machine with 100.000 runs each

// Testing '_string'
startsWith1 took 0.385906934738
startsWith2 took 0.457293987274
startsWith3 took 0.412894964218
startsWith4 took 0.366240024567 <-- fastest
startsWith5 took 0.642996072769
startsWith6 took 1.39859509468

// Tested "string"
startsWith1 took 0.384965896606
startsWith2 took 0.445554971695
startsWith3 took 0.42377281189
startsWith4 took 0.373164176941 <-- fastest
startsWith5 took 0.630424022675
startsWith6 took 1.40699005127

// Tested 1000 char random string [a-z0-9]
startsWith1 took 0.430691003799
startsWith2 took 4.447286129
startsWith3 took 0.413349866867
startsWith4 took 0.368592977524 <-- fastest
startsWith5 took 0.627470016479
startsWith6 took 1.40957403183

// Tested 1000 char random string [a-z0-9] with '_' prefix
startsWith1 took 0.384054899216
startsWith2 took 4.41522812843
startsWith3 took 0.408898115158
startsWith4 took 0.363884925842 <-- fastest
startsWith5 took 0.638479948044
startsWith6 took 1.41304707527

As you can see, treating the haystack as array to find out the char at the first position is always the fastest solution. It is also always performing at equal speed, regardless of string length. Using strpos is faster than substr for short strings but slower for long strings, when the string does not start with the prefix. The difference is irrelevant though. stripos is incredibly slow with long strings. preg_match performs mostly the same regardless of string length, but is only mediocre in speed. The mb_substr solution performs worst, while probably being more reliable though.

Given that these numbers are for 100.000 runs, it should be obvious that we are talking about 0.0000x seconds per call. Picking one over the other for efficiency is a worthless micro-optimization, unless your app is doing startsWith checking for a living.

Checking if a variable is an integer in PHP

Using is_numeric() for checking if a variable is an integer is a bad idea. This function will return TRUE for 3.14 for example. It's not the expected behavior.

To do this correctly, you can use one of these options:

Considering this variables array :

$variables = [
    "TEST 0" => 0,
    "TEST 1" => 42,
    "TEST 2" => 4.2,
    "TEST 3" => .42,
    "TEST 4" => 42.,
    "TEST 5" => "42",
    "TEST 6" => "a42",
    "TEST 7" => "42a",
    "TEST 8" => 0x24,
    "TEST 9" => 1337e0
];

The first option (FILTER_VALIDATE_INT way) :

# Check if your variable is an integer
if ( filter_var($variable, FILTER_VALIDATE_INT) === false ) {
  echo "Your variable is not an integer";
}

Output :

TEST 0 : 0 (type:integer) is an integer ?
TEST 1 : 42 (type:integer) is an integer ?
TEST 2 : 4.2 (type:double) is not an integer ?
TEST 3 : 0.42 (type:double) is not an integer ?
TEST 4 : 42 (type:double) is an integer ?
TEST 5 : 42 (type:string) is an integer ?
TEST 6 : a42 (type:string) is not an integer ?
TEST 7 : 42a (type:string) is not an integer ?
TEST 8 : 36 (type:integer) is an integer ?
TEST 9 : 1337 (type:double) is an integer ?

The second option (CASTING COMPARISON way) :

# Check if your variable is an integer
if ( strval($variable) !== strval(intval($variable)) ) {
  echo "Your variable is not an integer";
}

Output :

TEST 0 : 0 (type:integer) is an integer ?
TEST 1 : 42 (type:integer) is an integer ?
TEST 2 : 4.2 (type:double) is not an integer ?
TEST 3 : 0.42 (type:double) is not an integer ?
TEST 4 : 42 (type:double) is an integer ?
TEST 5 : 42 (type:string) is an integer ?
TEST 6 : a42 (type:string) is not an integer ?
TEST 7 : 42a (type:string) is not an integer ?
TEST 8 : 36 (type:integer) is an integer ?
TEST 9 : 1337 (type:double) is an integer ?

The third option (CTYPE_DIGIT way) :

# Check if your variable is an integer
if ( ! ctype_digit(strval($variable)) ) {
  echo "Your variable is not an integer";
}

Output :

TEST 0 : 0 (type:integer) is an integer ?
TEST 1 : 42 (type:integer) is an integer ?
TEST 2 : 4.2 (type:double) is not an integer ?
TEST 3 : 0.42 (type:double) is not an integer ?
TEST 4 : 42 (type:double) is an integer ?
TEST 5 : 42 (type:string) is an integer ?
TEST 6 : a42 (type:string) is not an integer ?
TEST 7 : 42a (type:string) is not an integer ?
TEST 8 : 36 (type:integer) is an integer ?
TEST 9 : 1337 (type:double) is an integer ?

The fourth option (REGEX way) :

# Check if your variable is an integer
if ( ! preg_match('/^\d+$/', $variable) ) {
  echo "Your variable is not an integer";
}

Output :

TEST 0 : 0 (type:integer) is an integer ?
TEST 1 : 42 (type:integer) is an integer ?
TEST 2 : 4.2 (type:double) is not an integer ?
TEST 3 : 0.42 (type:double) is not an integer ?
TEST 4 : 42 (type:double) is an integer ?
TEST 5 : 42 (type:string) is an integer ?
TEST 6 : a42 (type:string) is not an integer ?
TEST 7 : 42a (type:string) is not an integer ?
TEST 8 : 36 (type:integer) is an integer ?
TEST 9 : 1337 (type:double) is an integer ?

Is there an ignore command for git like there is for svn?

On Linux/Unix, you can append files to the .gitignore file with the echo command. For example if you want to ignore all .svn folders, run this from the root of the project:

echo .svn/ >> .gitignore

How do SETLOCAL and ENABLEDELAYEDEXPANSION work?

The ENABLEDELAYEDEXPANSION part is REQUIRED in certain programs that use delayed expansion, that is, that takes the value of variables that were modified inside IF or FOR commands by enclosing their names in exclamation-marks.

If you enable this expansion in a script that does not require it, the script behaves different only if it contains names enclosed in exclamation-marks !LIKE! !THESE!. Usually the name is just erased, but if a variable with the same name exist by chance, then the result is unpredictable and depends on the value of such variable and the place where it appears.

The SETLOCAL part is REQUIRED in just a few specialized (recursive) programs, but is commonly used when you want to be sure to not modify any existent variable with the same name by chance or if you want to automatically delete all the variables used in your program. However, because there is not a separate command to enable the delayed expansion, programs that require this must also include the SETLOCAL part.

How do I determine if my python shell is executing in 32bit or 64bit?

C:\Users\xyz>python

Python 2.7.6 (default, Nov XY ..., 19:24:24) **[MSC v.1500 64 bit (AMD64)] on win
32**
Type "help", "copyright", "credits" or "license" for more information.
>>>

after hitting python in cmd

Java compile error: "reached end of file while parsing }"

You need to enclose your class in { and }. A few extra pointers: According to the Java coding conventions, you should

  • Put your { on the same line as the method declaration:
  • Name your classes using CamelCase (with initial capital letter)
  • Name your methods using camelCase (with small initial letter)

Here's how I would write it:

public class ModMyMod extends BaseMod {

    public String version() {
         return "1.2_02";
    }

    public void addRecipes(CraftingManager recipes) {
       recipes.addRecipe(new ItemStack(Item.diamond), new Object[] {
          "#", Character.valueOf('#'), Block.dirt
       });
    }
}

How to set the first option on a select box using jQuery?

This is the most flexible/reusable way to reset all select boxes in your form.

      var $form = $('form') // Replace with your form selector
      $('select', $form).each(function() {
        $(this).val($(this).prop('defaultSelected'));
      });

How to install toolbox for MATLAB

first, you need to find the toolbox that you need. There are many people developing 3rd party toolboxes for Matlab, so there isn't just one single place where you can find "the image processing toolbox". That said, a good place to start looking is the Matlab Central which is a Mathworks-run site for exchanging all kinds of Matlab-related material.

Once you find a toolbox you want, it will be in some compressed format, and its developers might have a "readme" file that details on how to install it. If it isn't the case, a generic way to attempt installation is to place the toolbox in any directory on your drive, and then add it to Matlab path, e.g., going to File -> Set Path... -> Add Folder or Add with Subfolders (I'm writing for memory but this is definitely close).

Otherwise, you can extract all .m files in your working directory, if you don't want to use downloaded toolbox in more than one project.

What is the default initialization of an array in Java?

According to java,

Data Type - Default values

byte - 0

short - 0

int - 0

long - 0L

float - 0.0f

double - 0.0d

char - '\u0000'

String (or any object) - null

boolean - false

ansible : how to pass multiple commands

Shell works for me.

Simply to say, Shell is the same as you run a shell script.

Notes:

  1. Make sure use | when running multiple cmds.
  2. Shell won't return errors if the last cmd is success (just like normal shell)
  3. Control it with exit 0/1 if you want to stop ansible when error occurs.

The following example shows an error in shell, but it's success at the end of the execution.

- name: test shell with an error
become: no
shell: |
  rm -f /test1  # This should be an error.
  echo "test2"
  echo "test1"
  echo "test3" # success

This example shows stopinng shell with exit 1 error.

- name: test shell with exit 1
become: no
shell: |
  rm -f /test1  # This should be an error.
  echo "test2"
  exit 1        # this stops ansible due to returning an error
  echo "test1"
  echo "test3" # success

reference: https://docs.ansible.com/ansible/latest/modules/shell_module.html

Always show vertical scrollbar in <select>

I guess you cant, this maybe a limitation or not included in the IE browser. I have tried your jsfiddle with IE6-8 and all of it doesn't show the scrollbar and not sure with IE9. While in FF and chrome the scrollbar is shown. I also want to see how to do it in IE if possible.

If you really want to show the scrollbar, you can add a fake scrollbar. If you are familiar with some of the js library which use in RIA. Like in jquery/dojo some of the select is editable, because it is a combination of textbox + select or it can also be a textbox + div.

As an example, see it here a JavaScript that make select like editable.

pass parameter by link_to ruby on rails

The above did not work for me but this did

<%= link_to "text_to_show_in_url", action_controller_path(:gender => "male", :param2=> "something_else") %>

How to get the contents of a webpage in a shell variable?

You can use wget command to download the page and read it into a variable as:

content=$(wget google.com -q -O -)
echo $content

We use the -O option of wget which allows us to specify the name of the file into which wget dumps the page contents. We specify - to get the dump onto standard output and collect that into the variable content. You can add the -q quiet option to turn off's wget output.

You can use the curl command for this aswell as:

content=$(curl -L google.com)
echo $content

We need to use the -L option as the page we are requesting might have moved. In which case we need to get the page from the new location. The -L or --location option helps us with this.

Browser back button handling

You can also add hash when page is loading:

location.hash = "noBack";

Then just handle location hash change to add another hash:

$(window).on('hashchange', function() {
    location.hash = "noBack";
});

That makes hash always present and back button tries to remove hash at first. Hash is then added again by "hashchange" handler - so page would never actually can be changed to previous one.

Accessing AppDelegate from framework?

If you're creating a framework the whole idea is to make it portable. Tying a framework to the app delegate defeats the purpose of building a framework. What is it you need the app delegate for?

Why is the apt-get function not working in the terminal on Mac OS X v10.9 (Mavericks)?

Conda can also be used as package manager. It can be installed from Anaconda.

Alternatively, a free minimal installer is Miniconda.

Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop

You can use a while loop.

Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator();
while(iterator.hasNext()){
    Map.Entry<String, String> entry = iterator.next();
    if(entry.getKey().equals("test")) {
        iterator.remove();
    } 
}

PHP Notice: Undefined offset: 1 with array when reading data

This is a "PHP Notice", so you could in theory ignore it. Change php.ini:

error_reporting = E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED

To

error_reporting = E_ALL & ~E_NOTICE

This show all errors, except for notices.

Html code as IFRAME source rather than a URL

According to W3Schools, HTML 5 lets you do this using a new "srcdoc" attribute, but the browser support seems very limited.

PHP/regex: How to get the string value of HTML tag?

Since attribute values may contain a plain > character, try this regular expression:

$pattern = '/<'.preg_quote($tagname, '/').'(?:[^"'>]*|"[^"]*"|\'[^\']*\')*>(.*?)<\/'.preg_quote($tagname, '/').'>/s';

But regular expressions are not suitable for parsing non-regular languages like HTML. You should better use a parser like SimpleXML or DOMDocument.

ActionBar text color

Try adding this in your Activity's onCreate. Works on almost every Android version.

 actionBar.setTitle(Html.fromHtml("<font color='#ffff00'>Your Title</font>"));  

or

getSupportActionBar().setTitle(Html.fromHtml("<font color='#ffff00'>Your Title</font>"));

Java : Accessing a class within a package, which is the better way?

They're equivalent. The access is the same.

The import is just a convention to save you from having to type the fully-resolved class name each time. You can write all your Java without using import, as long as you're a fast touch typer.

But there's no difference in efficiency or class loading.

How to detect if a string contains special characters?

Assuming SQL Server:

e.g. if you class special characters as anything NOT alphanumeric:

DECLARE @MyString VARCHAR(100)
SET @MyString = 'adgkjb$'

IF (@MyString LIKE '%[^a-zA-Z0-9]%')
    PRINT 'Contains "special" characters'
ELSE
    PRINT 'Does not contain "special" characters'

Just add to other characters you don't class as special, inside the square brackets

Tkinter: How to use threads to preventing main event loop from "freezing"

I have used RxPY which has some nice threading functions to solve this in a fairly clean manner. No queues, and I have provided a function that runs on the main thread after completion of the background thread. Here is a working example:

import rx
from rx.scheduler import ThreadPoolScheduler
import time
import tkinter as tk

class UI:
   def __init__(self):
      self.root = tk.Tk()
      self.pool_scheduler = ThreadPoolScheduler(1) # thread pool with 1 worker thread
      self.button = tk.Button(text="Do Task", command=self.do_task).pack()

   def do_task(self):
      rx.empty().subscribe(
         on_completed=self.long_running_task, 
         scheduler=self.pool_scheduler
      )

   def long_running_task(self):
      # your long running task here... eg:
      time.sleep(3)
      # if you want a callback on the main thread:
      self.root.after(5, self.on_task_complete)

   def on_task_complete(self):
       pass # runs on main thread

if __name__ == "__main__":
    ui = UI()
    ui.root.mainloop()

Another way to use this construct which might be cleaner (depending on preference):

tk.Button(text="Do Task", command=self.button_clicked).pack()

...

def button_clicked(self):

   def do_task(_):
      time.sleep(3) # runs on background thread
             
   def on_task_done():
      pass # runs on main thread

   rx.just(1).subscribe(
      on_next=do_task, 
      on_completed=lambda: self.root.after(5, on_task_done), 
      scheduler=self.pool_scheduler
   )

LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

I got this error while I was trying to turn off precompiled headers in a Console Application Project and removing the header file stdafx.h

To fix this go to your project properties -> Linker -> SubSystem and change the value to Not Set

In your main class, use the standard C++ main function protoype that others have already mentioned :

int main(int argc, char** argv)

How to generate a create table script for an existing table in phpmyadmin?

Use the following query in sql tab:

SHOW CREATE TABLE tablename

To view full query There is this Hyperlink named +Options left above, There select Full Texts

Error System.Data.OracleClient requires Oracle client software version 8.1.7 or greater when installs setup

On your remote machine, System.Data.OracleClient need access to some of the oracle dll which are not part of .Net. Solutions:

  • Install Oracle Client , and add bin location to Path environment varaible of windows OR
  • Copy oraociicus10.dll (Basic-Lite version) or aociei10.dll (Basic version), oci.dll, orannzsbb10.dll and oraocci10.dll from oracle client installable folder to bin folder of application so that application is able to find required dll

On your local machine most probably path to Oracle Client is already added in Path environment variable to there required dll are available to application but not on remote machine

How to compare a local git branch with its remote branch?

If you're on a given branch, and you want to compare your working copy with the upstream branch you're tracking, use:

git diff @{upstream}

If you want to compare your current HEAD with the upstream branch (thanks @Arijoon):

git diff @ @{upstream}

If your upstream isn't set, you can use @{push} to get a diff against the branch you are set to push to (also from @Arijoon's comment):

git diff @{push}

Courtesy of this answer, the git documentation for specifying revisions has:

<branchname>@{upstream}, e.g. master@{upstream}, @{u}
The suffix @{upstream} to a branchname (short form <branchname>@{u}) refers to the branch that the branch specified by branchname is set to build on top of (configured with branch.<name>.remote and branch.<name>.merge). A missing branchname defaults to the current one.

Convert a list of objects to an array of one of the object's properties

This should also work:

AggregateValues("hello", MyList.ConvertAll(c => c.Name).ToArray())

USB Debugging option greyed out

Just ran into this on the LG Rebel LTE (LGL44VL). As other answers note, you need to change the USB connection mode to PTP. But my phone's control panels were different from stock Android and didn't have such an option.

The option was hiding in a notification that appeared when I plugged the phone in. I had to open the notification tray and tap a notification labeled

Media Device (MTP)
Tap here for more USB options

MySQL date formats - difficulty Inserting a date

When using a string-typed variable in PHP containing a date, the variable must be enclosed in single quotes:

$NEW_DATE = '1997-07-15';
$sql = "INSERT INTO tbl (NEW_DATE, ...) VALUES ('$NEW_DATE', ...)";

jQuery Toggle Text?

var el  = $('#someSelector');    
el.text(el.text() == 'view more' ? 'view less' : 'view more');

CSS Selector for <input type="?"

Sorry, the short answer is no. CSS (2.1) will only mark up the elements of a DOM, not their attributes. You'd have to apply a specific class to each input.

Bummer I know, because that would be incredibly useful.

I know you've said you'd prefer CSS over JavaScript, but you should still consider using jQuery. It provides a very clean and elegant way of adding styles to DOM elements based on attributes.

Convert a PHP object to an associative array

You can also create a function in PHP to convert an object array:

function object_to_array($object) {
    return (array) $object;
}

Get distance between two points in canvas

The distance between two coordinates x and y! x1 and y1 is the first point/position, x2 and y2 is the second point/position!

_x000D_
_x000D_
function diff (num1, num2) {_x000D_
  if (num1 > num2) {_x000D_
    return (num1 - num2);_x000D_
  } else {_x000D_
    return (num2 - num1);_x000D_
  }_x000D_
};_x000D_
_x000D_
function dist (x1, y1, x2, y2) {_x000D_
  var deltaX = diff(x1, x2);_x000D_
  var deltaY = diff(y1, y2);_x000D_
  var dist = Math.sqrt(Math.pow(deltaX, 2) + Math.pow(deltaY, 2));_x000D_
  return (dist);_x000D_
};
_x000D_
_x000D_
_x000D_

How to convert seconds to HH:mm:ss in moment.js

Until 24 hrs. As Duration.format is deprecated, with [email protected]

const seconds = 123;
moment.utc(moment.duration(seconds,'seconds').as('milliseconds')).format('HH:mm:ss');

Passing parameters on button action:@selector

I found solution. The call:

-(void) someMethod{
    UIButton * but;
    but.tag = 1;//some id button that you choice 
    [but addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside]; 
}

And here the method called:

-(void) buttonPressed : (id) sender{
    UIButton *clicked = (UIButton *) sender;
    NSLog(@"%d",clicked.tag);//Here you know which button has pressed
}

How to insert a text at the beginning of a file?

PROBLEM: tag a file, at the top of the file, with the base name of the parent directory.

I.e., for

/mnt/Vancouver/Programming/file1

tag the top of file1 with Programming.

SOLUTION 1 -- non-empty files:

bn=${PWD##*/}    ## bn: basename

sed -i '1s/^/'"$bn"'\n/' <file>

1s places the text at line 1 of the file.

SOLUTION 2 -- empty or non-empty files:

The sed command, above, fails on empty files. Here is a solution, based on https://superuser.com/questions/246837/how-do-i-add-text-to-the-beginning-of-a-file-in-bash/246841#246841

printf "${PWD##*/}\n" | cat - <file> > temp && mv -f temp <file>

Note that the - in the cat command is required (reads standard input: see man cat for more information). Here, I believe, it's needed to take the output of the printf statement (to STDIN), and cat that and the file to temp ... See also the explanation at the bottom of http://www.linfo.org/cat.html.

I also added -f to the mv command, to avoid being asked for confirmations when overwriting files.

To recurse over a directory:

for file in *; do printf "${PWD##*/}\n" | cat - $file > temp && mv -f temp $file; done

Note also that this will break over paths with spaces; there are solutions, elsewhere (e.g. file globbing, or find . -type f ... -type solutions) for those.

ADDENDUM: Re: my last comment, this script will allow you to recurse over directories with spaces in the paths:

#!/bin/bash

## https://stackoverflow.com/questions/4638874/how-to-loop-through-a-directory-recursively-to-delete-files-with-certain-extensi

## To allow spaces in filenames,
##   at the top of the script include: IFS=$'\n'; set -f
##   at the end of the script include: unset IFS; set +f

IFS=$'\n'; set -f

# ----------------------------------------------------------------------------
# SET PATHS:

IN="/mnt/Vancouver/Programming/data/claws-test/corpus test/"

# https://superuser.com/questions/716001/how-can-i-get-files-with-numeric-names-using-ls-command

# FILES=$(find $IN -type f -regex ".*/[0-9]*")        ## recursive; numeric filenames only
FILES=$(find $IN -type f -regex ".*/[0-9 ]*")         ## recursive; numeric filenames only (may include spaces)

# echo '$FILES:'                                      ## single-quoted, (literally) prints: $FILES:
# echo "$FILES"                                       ## double-quoted, prints path/, filename (one per line)

# ----------------------------------------------------------------------------
# MAIN LOOP:

for f in $FILES
do

  # Tag top of file with basename of current dir:
  printf "[top] Tag: ${PWD##*/}\n\n" | cat - $f > temp && mv -f temp $f

  # Tag bottom of file with basename of current dir:
  printf "\n[bottom] Tag: ${PWD##*/}\n" >> $f
done

unset IFS; set +f

Callback to a Fragment from a DialogFragment

Kotlin guys here we go!

So the problem we have is that we created an activity, MainActivity, on that activity we created a fragment, FragmentA and now we want to create a dialog fragment on top of FragmentA call it FragmentB. How do we get the results from FragmentB back to FragmentA without going through MainActivity?

Note:

  1. FragmentA is a child fragment of MainActivity. To manage fragments created in FragmentA we will use childFragmentManager which does that!
  2. FragmentA is a parent fragment of FragmentB, to access FragmentA from inside FragmentB we will use parenFragment.

Having said that, inside FragmentA,

class FragmentA : Fragment(), UpdateNameListener {
    override fun onSave(name: String) {
        toast("Running save with $name")
    }

    // call this function somewhere in a clickListener perhaps
    private fun startUpdateNameDialog() {
        FragmentB().show(childFragmentManager, "started name dialog")
    }
}

Here is the dialog fragment FragmentB.

class FragmentB : DialogFragment() {

    private lateinit var listener: UpdateNameListener

    override fun onAttach(context: Context) {
        super.onAttach(context)
        try {
            listener = parentFragment as UpdateNameListener
        } catch (e: ClassCastException) {
            throw ClassCastException("$context must implement UpdateNameListener")
        }
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        return activity?.let {
            val builder = AlertDialog.Builder(it)
            val binding = UpdateNameDialogFragmentBinding.inflate(LayoutInflater.from(context))
            binding.btnSave.setOnClickListener {
                val name = binding.name.text.toString()
                listener.onSave(name)
                dismiss()
            }
            builder.setView(binding.root)
            return builder.create()
        } ?: throw IllegalStateException("Activity can not be null")
    }
}

Here is the interface linking the two.

interface UpdateNameListener {
    fun onSave(name: String)
}

That's it.

What's the difference between dependencies, devDependencies and peerDependencies in npm package.json file?

peerDependencies didn't quite make sense for me until I read this snippet from a blog post on the topic Ciro mentioned above:

What [plugins] need is a way of expressing these “dependencies” between plugins and their host package. Some way of saying, “I only work when plugged in to version 1.2.x of my host package, so if you install me, be sure that it’s alongside a compatible host.” We call this relationship a peer dependency.

The plugin does expect a specific version of the host...

peerDependencies are for plugins, libraries that require a "host" library to perform their function, but may have been written at a time before the latest version of the host was released.

That is, if I write PluginX v1 for HostLibraryX v3 and walk away, there's no guarantee PluginX v1 will work when HostLibraryX v4 (or even HostLibraryX v3.0.1) is released.

... but the plugin doesn't depend on the host...

From the point of view of the plugin, it only adds functions to the host library. I don't really "need" the host to add a dependency to a plugin, and plugins often don't literally depend on their host. If you don't have the host, the plugin harmlessly does nothing.

This means dependencies isn't really the right concept for plugins.

Even worse, if my host was treated like a dependency, we'd end up in this situation that the same blog post mentions (edited a little to use this answer's made up host & plugin):

But now, [if we treat the contemporary version of HostLibraryX as a dependency for PluginX,] running npm install results in the unexpected dependency graph of

+-- [email protected]
+-- [email protected]
  +-- [email protected]

I’ll leave the subtle failures that come from the plugin using a different [HostLibraryX] API than the main application to your imagination.

... and the host obviously doesn't depend on the plugin...

... that's the whole point of plugins. Now if the host was nice enough to include dependency information for all of its plugins, that'd solve the problem, but that'd also introduce a huge new cultural problem: plugin management!

The whole point of plugins is that they can pair up anonymously. In a perfect world, having the host manage 'em all would be neat & tidy, but we're not going to require libraries herd cats.

If we're not hierarchically dependent, maybe we're intradependent peers...

Instead, we have the concept of being peers. Neither host nor plugin sits in the other's dependency bucket. Both live at the same level of the dependency graph.


... but this is not an automatable relationship. <<< Moneyball!!!

If I'm PluginX v1 and expect a peer of (that is, have a peerDependency of) HostLibraryX v3, I'll say so. If you've auto-upgraded to the latest HostLibraryX v4 (note that's version 4) AND have Plugin v1 installed, you need to know, right?

npm can't manage this situation for me --

"Hey, I see you're using PluginX v1! I'm automatically downgrading HostLibraryX from v4 to v3, kk?"

... or...

"Hey I see you're using PluginX v1. That expects HostLibraryX v3, which you've left in the dust during your last update. To be safe, I'm automatically uninstalling Plugin v1!!1!

How about no, npm?!

So npm doesn't. It alerts you to the situation, and lets you figure out if HostLibraryX v4 is a suitable peer for Plugin v1.


Coda

Good peerDependency management in plugins will make this concept work more intuitively in practice. From the blog post, yet again...

One piece of advice: peer dependency requirements, unlike those for regular dependencies, should be lenient. You should not lock your peer dependencies down to specific patch versions. It would be really annoying if one Chai plugin peer-depended on Chai 1.4.1, while another depended on Chai 1.5.0, simply because the authors were lazy and didn’t spend the time figuring out the actual minimum version of Chai they are compatible with.

Add Text on Image using PIL

One thing not mentioned in other answers is checking the text size. It is often needed to make sure the text fits the image (e.g. shorten the text if oversized) or to determine location to draw the text (e.g. aligned text top center). Pillow/PIL offers two methods to check the text size, one via ImageFont and one via ImageDraw. As shown below, the font doesn't handle multiple lined, while ImageDraw does.

In [28]: im = Image.new(mode='RGB',size=(240,240))                                                            
In [29]: font = ImageFont.truetype('arial')
In [30]: draw = ImageDraw.Draw(im)
In [31]: t1 = 'hello world!'
In [32]: t2 = 'hello \nworld!'
In [33]: font.getsize(t1), font.getsize(t2) # the height is the same
Out[33]: ((52, 10), (60, 10)) 
In [35]: draw.textsize(t1, font), draw.textsize(t2, font)  # handles multi-lined text
Out[35]: ((52, 10), (27, 24)) 

Warning message: In `...` : invalid factor level, NA generated

The warning message is because your "Type" variable was made a factor and "lunch" was not a defined level. Use the stringsAsFactors = FALSE flag when making your data frame to force "Type" to be a character.

> fixed <- data.frame("Type" = character(3), "Amount" = numeric(3))
> str(fixed)
'data.frame':   3 obs. of  2 variables:
 $ Type  : Factor w/ 1 level "": NA 1 1
 $ Amount: chr  "100" "0" "0"
> 
> fixed <- data.frame("Type" = character(3), "Amount" = numeric(3),stringsAsFactors=FALSE)
> fixed[1, ] <- c("lunch", 100)
> str(fixed)
'data.frame':   3 obs. of  2 variables:
 $ Type  : chr  "lunch" "" ""
 $ Amount: chr  "100" "0" "0"

How to check if std::map contains a key without doing insert?

Your desideratum,map.contains(key), is scheduled for the draft standard C++2a. In 2017 it was implemented by gcc 9.2. It's also in the current clang.

Matplotlib: ValueError: x and y must have same first dimension

Changing your lists to numpy arrays will do the job!!

import matplotlib.pyplot as plt
from scipy import stats
import numpy as np 

x = np.array([0.46,0.59,0.68,0.99,0.39,0.31,1.09,0.77,0.72,0.49,0.55,0.62,0.58,0.88,0.78]) # x is a numpy array now
y = np.array([0.315,0.383,0.452,0.650,0.279,0.215,0.727,0.512,0.478,0.335,0.365,0.424,0.390,0.585,0.511]) # y is a numpy array now
xerr = [0.01]*15
yerr = [0.001]*15

plt.rc('font', family='serif', size=13)
m, b = np.polyfit(x, y, 1)
plt.plot(x,y,'s',color='#0066FF')
plt.plot(x, m*x + b, 'r-') #BREAKS ON THIS LINE
plt.errorbar(x,y,xerr=xerr,yerr=0,linestyle="None",color='black')
plt.xlabel('$\Delta t$ $(s)$',fontsize=20)
plt.ylabel('$\Delta p$ $(hPa)$',fontsize=20)
plt.autoscale(enable=True, axis=u'both', tight=False)
plt.grid(False)
plt.xlim(0.2,1.2)
plt.ylim(0,0.8)
plt.show()

enter image description here

What is Node.js' Connect, Express and "middleware"?

The accepted answer is really old (and now wrong). Here's the information (with source) based on the current version of Connect (3.0) / Express (4.0).

What Node.js comes with

http / https createServer which simply takes a callback(req,res) e.g.

var server = http.createServer(function (request, response) {

    // respond
    response.write('hello client!');
    response.end();

});

server.listen(3000);

What connect adds

Middleware is basically any software that sits between your application code and some low level API. Connect extends the built-in HTTP server functionality and adds a plugin framework. The plugins act as middleware and hence connect is a middleware framework

The way it does that is pretty simple (and in fact the code is really short!). As soon as you call var connect = require('connect'); var app = connect(); you get a function app that can:

  1. Can handle a request and return a response. This is because you basically get this function
  2. Has a member function .use (source) to manage plugins (that comes from here because of this simple line of code).

Because of 1.) you can do the following :

var app = connect();

// Register with http
http.createServer(app)
    .listen(3000);

Combine with 2.) and you get:

var connect = require('connect');

// Create a connect dispatcher
var app = connect()
      // register a middleware
      .use(function (req, res, next) { next(); });

// Register with http
http.createServer(app)
    .listen(3000);

Connect provides a utility function to register itself with http so that you don't need to make the call to http.createServer(app). Its called listen and the code simply creates a new http server, register's connect as the callback and forwards the arguments to http.listen. From source

app.listen = function(){
  var server = http.createServer(this);
  return server.listen.apply(server, arguments);
};

So, you can do:

var connect = require('connect');

// Create a connect dispatcher and register with http
var app = connect()
          .listen(3000);
console.log('server running on port 3000');

It's still your good old http.createServer with a plugin framework on top.

What ExpressJS adds

ExpressJS and connect are parallel projects. Connect is just a middleware framework, with a nice use function. Express does not depend on Connect (see package.json). However it does the everything that connect does i.e:

  1. Can be registered with createServer like connect since it too is just a function that can take a req/res pair (source).
  2. A use function to register middleware.
  3. A utility listen function to register itself with http

In addition to what connect provides (which express duplicates), it has a bunch of more features. e.g.

  1. Has view engine support.
  2. Has top level verbs (get/post etc.) for its router.
  3. Has application settings support.

The middleware is shared

The use function of ExpressJS and connect is compatible and therefore the middleware is shared. Both are middleware frameworks, express just has more than a simple middleware framework.

Which one should you use?

My opinion: you are informed enough ^based on above^ to make your own choice.

  • Use http.createServer if you are creating something like connect / expressjs from scratch.
  • Use connect if you are authoring middleware, testing protocols etc. since it is a nice abstraction on top of http.createServer
  • Use ExpressJS if you are authoring websites.

Most people should just use ExpressJS.

What's wrong about the accepted answer

These might have been true as some point in time, but wrong now:

that inherits an extended version of http.Server

Wrong. It doesn't extend it and as you have seen ... uses it

Express does to Connect what Connect does to the http module

Express 4.0 doesn't even depend on connect. see the current package.json dependencies section

Xcode "Build and Archive" from command line

try xctool, it is a replacement for Apple's xcodebuild that makes it easier to build and test iOS and Mac products. It's especially helpful for continuous integration. It has a few extra features:

  1. Runs the same tests as Xcode.app.
  2. Structured output of build and test results.
  3. Human-friendly, ANSI-colored output.

No.3 is extremely useful. I don't if anyone can read the console output of xcodebuild, I can't, usually it gave me one line with 5000+ characters. Even harder to read than a thesis paper.

xctool: https://github.com/facebook/xctool

How to store decimal values in SQL Server?

In MySQL DB decimal(4,2) allows entering only a total of 4 digits. As you see in decimal(4,2), it means you can enter a total of 4 digits out of which two digits are meant for keeping after the decimal point.

So, if you enter 100.0 in MySQL database, it will show an error like "Out of Range Value for column".

So, you can enter in this range only: from 00.00 to 99.99.

Check if textbox has empty value

if ( $("#txt").val().length > 0 )
{
  // do something
}

Your method fails when there is more than 1 space character inside the textbox.

How to modify a specified commit?

Use the awesome interactive rebase:

git rebase -i @~9   # Show the last 9 commits in a text editor

Find the commit you want, change pick to e (edit), and save and close the file. Git will rewind to that commit, allowing you to either:

  • use git commit --amend to make changes, or
  • use git reset @~ to discard the last commit, but not the changes to the files (i.e. take you to the point you were at when you'd edited the files, but hadn't committed yet).

The latter is useful for doing more complex stuff like splitting into multiple commits.

Then, run git rebase --continue, and Git will replay the subsequent changes on top of your modified commit. You may be asked to fix some merge conflicts.

Note: @ is shorthand for HEAD, and ~ is the commit before the specified commit.

Read more about rewriting history in the Git docs.


Don't be afraid to rebase

ProTip™:   Don't be afraid to experiment with "dangerous" commands that rewrite history* — Git doesn't delete your commits for 90 days by default; you can find them in the reflog:

$ git reset @~3   # go back 3 commits
$ git reflog
c4f708b HEAD@{0}: reset: moving to @~3
2c52489 HEAD@{1}: commit: more changes
4a5246d HEAD@{2}: commit: make important changes
e8571e4 HEAD@{3}: commit: make some changes
... earlier commits ...
$ git reset 2c52489
... and you're back where you started

* Watch out for options like --hard and --force though — they can discard data.
* Also, don't rewrite history on any branches you're collaborating on.



On many systems, git rebase -i will open up Vim by default. Vim doesn't work like most modern text editors, so take a look at how to rebase using Vim. If you'd rather use a different editor, change it with git config --global core.editor your-favorite-text-editor.

How do I make a <div> move up and down when I'm scrolling the page?

Just for a more animated and cute solution:

$(window).scroll(function(){
  $("#div").stop().animate({"marginTop": ($(window).scrollTop()) + "px", "marginLeft":($(window).scrollLeft()) + "px"}, "slow" );
});

And a pen for those who want to see: http://codepen.io/think123/full/mAxlb, and fork: http://codepen.io/think123/pen/mAxlb

Update: and a non-animated jQuery solution:

$(window).scroll(function(){
  $("#div").css({"margin-top": ($(window).scrollTop()) + "px", "margin-left":($(window).scrollLeft()) + "px"});
});

How can I get a vertical scrollbar in my ListBox?

In my case the number of items in the ListBox is dynamic so I didn't want to use the Height property. I used MaxHeight instead and it works nicely. The scrollbar appears when it fills the space I've allocated for it.

Type of expression is ambiguous without more context Swift

I had this message when the type of a function parameter didn't fit. In my case it was a String instead of an URL.

How to compare only date in moment.js

In my case i did following code for compare 2 dates may it will help you ...

_x000D_
_x000D_
var date1 = "2010-10-20";_x000D_
var date2 = "2010-10-20";_x000D_
var time1 = moment(date1).format('YYYY-MM-DD');_x000D_
var time2 = moment(date2).format('YYYY-MM-DD');_x000D_
if(time2 > time1){_x000D_
 console.log('date2 is Greter than date1');_x000D_
}else if(time2 > time1){_x000D_
 console.log('date2 is Less than date1');_x000D_
}else{_x000D_
 console.log('Both date are same');_x000D_
}
_x000D_
<script src="https://momentjs.com/downloads/moment.js"></script>
_x000D_
_x000D_
_x000D_

HTML select drop-down with an input field

You can use input text with "list" attribute, which refers to the datalist of values.

_x000D_
_x000D_
<input type="text" name="city" list="cityname">_x000D_
    <datalist id="cityname">_x000D_
      <option value="Boston">_x000D_
      <option value="Cambridge">_x000D_
    </datalist>
_x000D_
_x000D_
_x000D_

This creates a free text input field that also has a drop-down to select predefined choices. Attribution for example and more information: https://www.w3.org/wiki/HTML/Elements/datalist

How to "grep" for a filename instead of the contents of a file?

Example

find <path> -name *FileName*

From manual:

find -name pattern

Base of file name (the path with the leading directories removed) matches shell pattern pattern. Because the leading directories are removed, the file names considered for a match with -name will never include a slash, so "-name a/b" will never match anything (you probably need to use -path instead). The metacharacters ("*", "?", and "[]") match a "." at the start of the base name (this is a change in find- utils-4.2.2; see section STANDARDS CONFORMANCE below). To ignore a directory and the files under it, use -prune; see an example in the description of -path. Braces are not recognised as being special, despite the fact that some shells including Bash imbue braces with a special meaning in shell patterns. The filename matching is performed with the use of the fnmatch(3) library function. Don't forget to enclose the pattern in quotes in order to protect it from expansion by the shell.

Is there a decent wait function in C++?

getchar() provides a simplistic answer (waits for keyboard input). Call Sleep(milliseconds) to sleep before exit. Sleep function (MSDN)

linux execute command remotely

 ssh user@machine 'bash -s' < local_script.sh

or you can just

 ssh user@machine "remote command to run" 

Razor/CSHTML - Any Benefit over what we have?

The biggest benefit is that the code is more succinct. The VS editor will also have the IntelliSense support that some of the other view engines don't have.

Declarative HTML Helpers also look pretty cool as doing HTML helpers within C# code reminds me of custom controls in ASP.NET. I think they took a page from partials but with the inline code.

So some definite benefits over the asp.net view engine.

With contrast to a view engine like spark though:

Spark is still more succinct, you can keep the if's and loops within a html tag itself. The markup still just feels more natural to me.

You can code partials exactly how you would do a declarative helper, you'd just pass along the variables to the partial and you have the same thing. This has been around with spark for quite awhile.

How to upgrade Angular CLI project?

Just use the build-in feature of Angular CLI

ng update

to update to the latest version.

Cannot serve WCF services in IIS on Windows 8

Seemed to be a no brainer; the WCF service should be enabled using Programs and Features -> Turn Windows features on or off in the Control Panel. Go to .NET Framework Advanced Services -> WCF Services and enable HTTP Activation as described in this blog post on mdsn.

From the command prompt (as admin), you can run:

C:\> DISM /Online /Enable-Feature /FeatureName:WCF-HTTP-Activation
C:\> DISM /Online /Enable-Feature /FeatureName:WCF-HTTP-Activation45

If you get an error then use the below

C:\> DISM /Online /Enable-Feature /all /FeatureName:WCF-HTTP-Activation
C:\> DISM /Online /Enable-Feature /all /FeatureName:WCF-HTTP-Activation45

Initialize value of 'var' in C# to null

The var keyword in C#'s main benefit is to enhance readability, not functionality. Technically, the var keywords allows for some other unlocks (e.g. use of anonymous objects), but that seems to be outside the scope of this question. Every variable declared with the var keyword has a type. For instance, you'll find that the following code outputs "String".

var myString = "";
Console.Write(myString.GetType().Name);

Furthermore, the code above is equivalent to:

String myString = "";
Console.Write(myString.GetType().Name);

The var keyword is simply C#'s way of saying "I can figure out the type for myString from the context, so don't worry about specifying the type."

var myVariable = (MyType)null or MyType myVariable = null should work because you are giving the C# compiler context to figure out what type myVariable should will be.

For more information:

How can I force division to be floating point? Division keeps rounding down to 0?

from operator import truediv

c = truediv(a, b)

where a is dividend and b is the divisor. This function is handy when quotient after division of two integers is a float.

Getting list of lists into pandas DataFrame

Even without pop the list we can do with set_index

pd.DataFrame(table).T.set_index(0).T
Out[11]: 
0 Heading1 Heading2
1        1        2
2        3        4

Update from_records

table = [['Heading1', 'Heading2'], [1 , 2], [3, 4]]

pd.DataFrame.from_records(table[1:],columns=table[0])
Out[58]: 
   Heading1  Heading2
0         1         2
1         3         4

Comparing two files in linux terminal

Sort them and use comm:

comm -23 <(sort a.txt) <(sort b.txt)

comm compares (sorted) input files and by default outputs three columns: lines that are unique to a, lines that are unique to b, and lines that are present in both. By specifying -1, -2 and/or -3 you can suppress the corresponding output. Therefore comm -23 a b lists only the entries that are unique to a. I use the <(...) syntax to sort the files on the fly, if they are already sorted you don't need this.

Create a map with clickable provinces/states using SVG, HTML/CSS, ImageMap

Sounds like you want a simple imagemap, I'd recommend to not make it more complex than it needs to be. Here's an article on how to improve imagemaps with svg. It's very easy to do clickable regions in svg itself, just add some <a> elements around the shapes you want to have clickable.

A couple of options if you need something more advanced:

Unpivot with column name

Your query is very close. You should be able to use the following which includes the subject in the final select list:

select u.name, u.subject, u.marks
from student s
unpivot
(
  marks
  for subject in (Maths, Science, English)
) u;

See SQL Fiddle with demo

ASP.net vs PHP (What to choose)

You can have great success and great performance either way. MSDN runs off of ASP.NET so you know it can perform well. PHP runs a lot of the top websites in the world. The same can be said of the databases as well. You really need to choose based upon your skills, the skills of your team, possible specific features that you need/want that one does better than the other, and even the servers that you want to run this site.

If I were building it, I would lean towards PHP because probably everything you want to do has been done before (with code examples how) and because hosting is so much easier to get (and cheaper because you don't have the licensing issues to deal with compared to Windows hosting). For the same reason, I would choose MySQL as well. It is a great database platform and the price is right.

How to add an action to a UIAlertView button using Swift iOS

based on swift:

let alertCtr = UIAlertController(title:"Title", message:"Message", preferredStyle: .Alert)
let Cancel = AlertAction(title:"remove", style: .Default, handler: {(UIAlertAction) -> Void in })
let Remove = UIAlertAction(title:"remove", style: .Destructive, handler:{(UIAlertAction)-> Void 
    inself.colorLabel.hidden = true    
})
alertCtr.addAction(Cancel)
alertCtr.addAction(Remove)

self.presentViewController(alertCtr, animated:true, completion:nil)}

TypeError: 'bool' object is not callable

You do cls.isFilled = True. That overwrites the method called isFilled and replaces it with the value True. That method is now gone and you can't call it anymore. So when you try to call it again you get an error, since it's not there anymore.

The solution is use a different name for the variable than you do for the method.

Check if argparse optional argument is set or not

I think that optional arguments (specified with --) are initialized to None if they are not supplied. So you can test with is not None. Try the example below:

import argparse as ap

def main():
    parser = ap.ArgumentParser(description="My Script")
    parser.add_argument("--myArg")
    args, leftovers = parser.parse_known_args()

    if args.myArg is not None:
        print "myArg has been set (value is %s)" % args.myArg

Regular expression for checking if capital letters are found consecutively in a string?

^([A-Z][a-z]+)+$

This looks for sequences of an uppercase letter followed by one or more lowercase letters. Consecutive uppercase letters will not match, as only one is allowed at a time, and it must be followed by a lowercase one.

How do I get a button to open another activity?

Button T=(Button)findViewById(R.id.button_timer);
T.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        Intent i=new Intent(getApplicationContext(),YOURACTIVITY.class);
        startActivity(i);
    }
});

Cookie blocked/not saved in IFRAME in Internet Explorer

A better solution would be to make an Ajax call inside the iframe to the page that would get/set cookies...

How do I set GIT_SSL_NO_VERIFY for specific repos only?

If you have to disable SSL checks for one git server hosting several repositories, you can run :

git config --bool --add http.https://my.bad.server.sslverify false

This will add it to your user's configuration.

Command to check:

git config --bool --get-urlmatch http.sslverify https://my.bad.server 

(If you still use git < v1.8.5, run git config --global http.https://my.bad.server.sslVerify false)

Explanation from the documentation where the command is at the end, show the .gitconfig content looking like:

[http "https://my.bad.server"]
        sslVerify = false

It will ignore any certificate checks for this server, whatever the repository.

You also have some explanation in the code

How to center the elements in ConstraintLayout

add these tag in your view

    app:layout_constraintCircleRadius="0dp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.5"
    app:layout_constraintStart_toStartOf="parent"

and you can right click in design mode and choose center.

RestClientException: Could not extract response. no suitable HttpMessageConverter found

Please add the shared dependency having jackson databind package . Hope this will clear the issue.

  <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.12.1</version>
  </dependency>

Difference between os.getenv and os.environ.get

While there is no functional difference between os.environ.get and os.getenv, there is a massive difference between os.putenv and setting entries on os.environ. os.putenv is broken, so you should default to os.environ.get simply to avoid the way os.getenv encourages you to use os.putenv for symmetry.

os.putenv changes the actual OS-level environment variables, but in a way that doesn't show up through os.getenv, os.environ, or any other stdlib way of inspecting environment variables:

>>> import os
>>> os.environ['asdf'] = 'fdsa'
>>> os.environ['asdf']
'fdsa'
>>> os.putenv('aaaa', 'bbbb')
>>> os.getenv('aaaa')
>>> os.environ.get('aaaa')

You'd probably have to make a ctypes call to the C-level getenv to see the real environment variables after calling os.putenv. (Launching a shell subprocess and asking it for its environment variables might work too, if you're very careful about escaping and --norc/--noprofile/anything else you need to do to avoid startup configuration, but it seems a lot harder to get right.)

How to create an Oracle sequence starting with max value from a table?

If you can use PL/SQL, try (EDIT: Incorporates Neil's xlnt suggestion to start at next higher value):

SELECT 'CREATE SEQUENCE transaction_sequence MINVALUE 0 START WITH '||MAX(trans_seq_no)+1||' INCREMENT BY 1 CACHE 20'
  INTO v_sql
  FROM transaction_log;

EXECUTE IMMEDIATE v_sql;

Another point to consider: By setting the CACHE parameter to 20, you run the risk of losing up to 19 values in your sequence if the database goes down. CACHEd values are lost on database restarts. Unless you're hitting the sequence very often, or, you don't care that much about gaps, I'd set it to 1.

One final nit: the values you specified for CACHE and INCREMENT BY are the defaults. You can leave them off and get the same result.

Change value of input onchange?

for jQuery we can use below:

by input name:

$('input[name="textboxname"]').val('some value');

by input class:

$('input[type=text].textboxclass').val('some value');

by input id:

$('#textboxid').val('some value');

How do I check form validity with angularjs?

When you put <form> tag inside you ngApp, AngularJS automatically adds form controller (actually there is a directive, called form that add nessesary behaviour). The value of the name attribute will be bound in your scope; so something like <form name="yourformname">...</form> will satisfy:

A form is an instance of FormController. The form instance can optionally be published into the scope using the name attribute.

So to check form validity, you can check value of $scope.yourformname.$valid property of scope.

More information you can get at Developer's Guide section about forms.

Display Python datetime without time

For me, I needed to KEEP a timetime object because I was using UTC and it's a bit of a pain. So, this is what I ended up doing:

date = datetime.datetime.utcnow()

start_of_day = date - datetime.timedelta(
    hours=date.hour, 
    minutes=date.minute, 
    seconds=date.second, 
    microseconds=date.microsecond
)

end_of_day = start_of_day + datetime.timedelta(
    hours=23, 
    minutes=59, 
    seconds=59
)

Example output:

>>> date
datetime.datetime(2016, 10, 14, 17, 21, 5, 511600)
>>> start_of_day
datetime.datetime(2016, 10, 14, 0, 0)
>>> end_of_day
datetime.datetime(2016, 10, 14, 23, 59, 59)

How to export JSON from MongoDB using Robomongo

you say "export to file" as in a spreadsheet? like to a .csv?

IMO this is the EASIEST way to do this in Robo 3T (formerly robomongo):

  1. In the top right of the Robo 3T GUI there is a "View Results in text mode" button, click it and copy everything

  2. paste everything into this website: https://json-csv.com/

  3. click the download button and now you have it in a spreadsheet.

hope this helps someone, as I wish Robo 3T had export capabilities

Fully backup a git repo?

This thread was very helpful to get some insights how backups of git repos could be done. I think it still lacks some hints, information or conclusion to find the "correct way" (tm) for oneself. Therefore sharing my thoughts here to help others and put them up for discussions to enhance them. Thanks.

So starting with picking-up the original question:

  • Goal is to get as close as possible to a "full" backup of a git repository.

Then enriching it with the typical wishes and specifiying some presettings:

  • Backup via a "hot-copy" is preferred to avoid service downtime.
  • Shortcomings of git will be worked around by additional commands.
  • A script should do the backup to combine the multiple steps for a single backup and to avoid human mistakes (typos, etc.).
  • Additionally a script should do the restore to adapt the dump to the target machine, e.g. even the configuration of the original machine may have changed since the backup.
  • Environment is a git server on a Linux machine with a file system that supports hardlinks.

1. What is a "full" git repo backup?

The point of view differs on what a "100%" backup is. Here are two typical ones.

#1 Developer's point of view

  • Content
  • References

git is a developer tool and supports this point of view via git clone --mirror and git bundle --all.

#2 Admin's point of view

  • Content files
    • Special case "packfile": git combines and compacts objects into packfiles during garbage collection (see git gc)
  • git configuration
  • Optional: OS configuration (file system permissions, etc.)

git is a developer tool and leaves this to the admin. Backup of the git configuration and OS configuration should be seen as separated from the backup of the content.

2. Techniques

  • "Cold-Copy"
    • Stop the service to have exclusive access to its files. Downtime!
  • "Hot-Copy"
    • Service provides a fixed state for backup purposes. On-going changes do not affect that state.

3. Other topics to think about

Most of them are generic for backups.

  • Is there enough space to hold the full backups? How many generations will be stored?
  • Is an incremental approach wanted? How many generations will be stored and when to create a full backup again?
  • How to verify that a backup is not corrupted after creation or over time?
  • Does the file system support hardlinks?
  • Put backup into a single archive file or use directory structure?

4. What git provides to backup content

  • git gc --auto

    • docs: man git-gc
    • Cleans up and compacts a repository.
  • git bundle --all

    • docs: man git-bundle, man git-rev-list
    • Atomic = "Hot-Copy"
    • Bundles are dump files and can be directly used with git (verify, clone, etc.).
    • Supports incremental extraction.
    • Verifiable via git bundle verify.
  • git clone --mirror

    • docs: man git-clone, man git-fsck, What's the difference between git clone --mirror and git clone --bare
    • Atomic = "Hot-Copy"
    • Mirrors are real git repositories.
    • Primary intention of this command is to build a full active mirror, that periodically fetches updates from the original repository.
    • Supports hardlinks for mirrors on same file system to avoid wasting space.
    • Verifiable via git fsck.
    • Mirrors can be used as a basis for a full file backup script.

5. Cold-Copy

A cold-copy backup can always do a full file backup: deny all accesses to the git repos, do backup and allow accesses again.

  • Possible Issues
    • May not be easy - or even possible - to deny all accesses, e.g. shared access via file system.
    • Even if the repo is on a client-only machine with a single user, then the user still may commit something during an automated backup run :(
    • Downtime may not be acceptable on server and doing a backup of multiple huge repos can take a long time.
  • Ideas for Mitigation:
    • Prevent direct repo access via file system in general, even if clients are on the same machine.
    • For SSH/HTTP access use git authorization managers (e.g. gitolite) to dynamically manage access or modify authentication files in a scripted way.
    • Backup repos one-by-one to reduce downtime for each repo. Deny one repo, do backup and allow access again, then continue with the next repo.
    • Have planned maintenance schedule to avoid upset of developers.
    • Only backup when repository has changed. Maybe very hard to implement, e.g. list of objects plus having packfiles in mind, checksums of config and hooks, etc.

6. Hot-Copy

File backups cannot be done with active repos due to risk of corrupted data by on-going commits. A hot-copy provides a fixed state of an active repository for backup purposes. On-going commits do not affect that copy. As listed above git's clone and bundle functionalities support this, but for a "100% admin" backup several things have to be done via additional commands.

"100% admin" hot-copy backup

  • Option 1: use git bundle --all to create full/incremental dump files of content and copy/backup configuration files separately.
  • Option 2: use git clone --mirror, handle and copy configuration separately, then do full file backup of mirror.
    • Notes:
    • A mirror is a new repository, that is populated with the current git template on creation.
    • Clean up configuration files and directories, then copy configuration files from original source repository.
    • Backup script may also apply OS configuration like file permissions on the mirror.
    • Use a filesystem that supports hardlinks and create the mirror on the same filesystem as the source repository to gain speed and reduce space consumption during backup.

7. Restore

  • Check and adopt git configuration to target machine and latest "way of doing" philosophy.
  • Check and adopt OS configuration to target machine and latest "way of doing" philosophy.

Get Row Index on Asp.net Rowcommand event

Or, you can use a control class instead of their types:

GridViewRow row = (GridViewRow)(((Control)e.CommandSource).NamingContainer);

int RowIndex = row.RowIndex; 

Default string initialization: NULL or Empty?

Why do you want your string to be initialized at all? You don't have to initialize a variable when you declare one, and IMO, you should only do so when the value you are assigning is valid in the context of the code block.

I see this a lot:

string name = null; // or String.Empty
if (condition)
{
  name = "foo";
}
else
{
  name = "bar";
}

return name;

Not initializing to null would be just as effective. Furthermore, most often you want a value to be assigned. By initializing to null, you can potentially miss code paths that don't assign a value. Like so:

string name = null; // or String.Empty
if (condition)
{
  name = "foo";
}
else if (othercondition)
{
  name = "bar";
}

return name; //returns null when condition and othercondition are false

When you don't initialize to null, the compiler will generate an error saying that not all code paths assign a value. Of course, this is a very simple example...

Matthijs

How to Import Excel file into mysql Database from PHP

You are probably having a problem with the sort of CSV file that you have.

Open the CSV file with a text editor, check that all the separations are done with the comma, and not semicolon and try the script again. It should work fine.

Playing a MP3 file in a WinForm application

The link below, gives a very good tutorial, about playing mp3 files from a windows form with c#:

http://www.daniweb.com/software-development/csharp/threads/292695/playing-mp3-in-c

This link will lead you to a topic, which contains a lot information about how to play an mp3 song, using Windows forms. It also contains a lot of other projects, trying to achieve the same thing:

http://social.msdn.microsoft.com/forums/en-US/csharpgeneral/thread/3dbfb9a3-4e14-41d1-afbb-1790420706fe

For example use this code for .mp3:

WMPLib.WindowsMediaPlayer wplayer = new WMPLib.WindowsMediaPlayer();

wplayer.URL = "My MP3 file.mp3";
wplayer.Controls.Play();

Then only put the wplayer.Controls.Play(); in the Button_Click event.

For example use this code for .wav:

System.Media.SoundPlayer player = new System.Media.SoundPlayer();

player.SoundLocation = "Sound.wav";
player.Play();

Put the player.Play(); in the Button_Click event, and it will work.

How to get first character of string?

Example of all method

First : string.charAt(index)

Return the caract at the index index

_x000D_
_x000D_
var str = "Stack overflow";_x000D_
_x000D_
console.log(str.charAt(0));
_x000D_
_x000D_
_x000D_

Second : string.substring(start,length);

Return the substring in the string who start at the index start and stop after the length length

Here you only want the first caract so : start = 0 and length = 1

_x000D_
_x000D_
var str = "Stack overflow";_x000D_
_x000D_
console.log(str.substring(0,1));
_x000D_
_x000D_
_x000D_

Alternative : string[index]

A string is an array of caract. So you can get the first caract like the first cell of an array.

Return the caract at the index index of the string

_x000D_
_x000D_
var str = "Stack overflow";_x000D_
_x000D_
console.log(str[0]);
_x000D_
_x000D_
_x000D_

File.separator vs FileSystem.getSeparator() vs System.getProperty("file.separator")?

System.getProperties() can be overridden by calls to System.setProperty(String key, String value) or with command line parameters -Dfile.separator=/

File.separator gets the separator for the default filesystem.

FileSystems.getDefault() gets you the default filesystem.

FileSystem.getSeparator() gets you the separator character for the filesystem. Note that as an instance method you can use this to pass different filesystems to your code other than the default, in cases where you need your code to operate on multiple filesystems in the one JVM.

How can I recover the return value of a function passed to multiprocessing.Process?

I think the approach suggested by @sega_sai is the better one. But it really needs a code example, so here goes:

import multiprocessing
from os import getpid

def worker(procnum):
    print('I am number %d in process %d' % (procnum, getpid()))
    return getpid()

if __name__ == '__main__':
    pool = multiprocessing.Pool(processes = 3)
    print(pool.map(worker, range(5)))

Which will print the return values:

I am number 0 in process 19139
I am number 1 in process 19138
I am number 2 in process 19140
I am number 3 in process 19139
I am number 4 in process 19140
[19139, 19138, 19140, 19139, 19140]

If you are familiar with map (the Python 2 built-in) this should not be too challenging. Otherwise have a look at sega_Sai's link.

Note how little code is needed. (Also note how processes are re-used).

Declaring abstract method in TypeScript

The name property is marked as protected. This was added in TypeScript 1.3 and is now firmly established.

The makeSound method is marked as abstract, as is the class. You cannot directly instantiate an Animal now, because it is abstract. This is part of TypeScript 1.6, which is now officially live.

abstract class Animal {
    constructor(protected name: string) { }

    abstract makeSound(input : string) : string;

    move(meters) {
        alert(this.name + " moved " + meters + "m.");
    }
}

class Snake extends Animal {
    constructor(name: string) { super(name); }

    makeSound(input : string) : string {
        return "sssss"+input;
    }

    move() {
        alert("Slithering...");
        super.move(5);
    }
}

The old way of mimicking an abstract method was to throw an error if anyone used it. You shouldn't need to do this any more once TypeScript 1.6 lands in your project:

class Animal {
    constructor(public name) { }
    makeSound(input : string) : string {
        throw new Error('This method is abstract');
    }
    move(meters) {
        alert(this.name + " moved " + meters + "m.");
    }
}

class Snake extends Animal {
    constructor(name) { super(name); }
    makeSound(input : string) : string {
        return "sssss"+input;
    }
    move() {
        alert("Slithering...");
        super.move(5);
    }
}

Set value of textbox using JQuery

You're targeting the wrong item with that jQuery selector. The name of your search bar is searchBar, not the id. What you want to use is $('#main_search').val('hi').

Object of class DateTime could not be converted to string

Try this:

$Date = $row['valdate']->format('d/m/Y'); // the result will 01/12/2015

NOTE: $row['valdate'] its a value date in the database

What's the difference between window.location= and window.location.replace()?

TLDR;

use location.href or better use window.location.href;

However if you read this you will gain undeniable proof.

The truth is it's fine to use but why do things that are questionable. You should take the higher road and just do it the way that it probably should be done.

location = "#/mypath/otherside"
var sections = location.split('/')

This code is perfectly correct syntax-wise, logic wise, type-wise you know the only thing wrong with it?

it has location instead of location.href

what about this

var mystring = location = "#/some/spa/route"

what is the value of mystring? does anyone really know without doing some test. No one knows what exactly will happen here. Hell I just wrote this and I don't even know what it does. location is an object but I am assigning a string will it pass the string or pass the location object. Lets say there is some answer to how this should be implemented. Can you guarantee all browsers will do the same thing?

This i can pretty much guess all browsers will handle the same.

var mystring = location.href = "#/some/spa/route"

What about if you place this into typescript will it break because the type compiler will say this is suppose to be an object?

This conversation is so much deeper than just the location object however. What this conversion is about what kind of programmer you want to be?

If you take this short-cut, yea it might be okay today, ye it might be okay tomorrow, hell it might be okay forever, but you sir are now a bad programmer. It won't be okay for you and it will fail you.

There will be more objects. There will be new syntax.

You might define a getter that takes only a string but returns an object and the worst part is you will think you are doing something correct, you might think you are brilliant for this clever method because people here have shamefully led you astray.

var Person.name = {first:"John":last:"Doe"}
console.log(Person.name) // "John Doe"

With getters and setters this code would actually work, but just because it can be done doesn't mean it's 'WISE' to do so.

Most people who are programming love to program and love to get better. Over the last few years I have gotten quite good and learn a lot. The most important thing I know now especially when you write Libraries is consistency and predictability.

Do the things that you can consistently do.

+"2" <-- this right here parses the string to a number. should you use it? or should you use parseInt("2")?

what about var num =+"2"?

From what you have learn, from the minds of stackoverflow i am not too hopefully.

If you start following these 2 words consistent and predictable. You will know the right answer to a ton of questions on stackoverflow.

Let me show you how this pays off. Normally I place ; on every line of javascript i write. I know it's more expressive. I know it's more clear. I have followed my rules. One day i decided not to. Why? Because so many people are telling me that it is not needed anymore and JavaScript can do without it. So what i decided to do this. Now because I have become sure of my self as a programmer (as you should enjoy the fruit of mastering a language) i wrote something very simple and i didn't check it. I erased one comma and I didn't think I needed to re-test for such a simple thing as removing one comma.

I wrote something similar to this in es6 and babel

var a = "hello world"
(async function(){
  //do work
})()

This code fail and took forever to figure out. For some reason what it saw was

var a = "hello world"(async function(){})()

hidden deep within the source code it was telling me "hello world" is not a function.

For more fun node doesn't show the source maps of transpiled code.

Wasted so much stupid time. I was presenting to someone as well about how ES6 is brilliant and then I had to start debugging and demonstrate how headache free and better ES6 is. Not convincing is it.

I hope this answered your question. This being an old question it's more for the future generation, people who are still learning.

Question when people say it doesn't matter either way works. Chances are a wiser more experienced person will tell you other wise.

what if someone overwrite the location object. They will do a shim for older browsers. It will get some new feature that needs to be shimmed and your 3 year old code will fail.

My last note to ponder upon.

Writing clean, clear purposeful code does something for your code that can't be answer with right or wrong. What it does is it make your code an enabler.

You can use more things plugins, Libraries with out fear of interruption between the codes.

for the record. use

window.location.href

Using group by on two fields and count in SQL

SELECT group,subGroup,COUNT(*) FROM tablename GROUP BY group,subgroup

How do I find the width & height of a terminal window?

On POSIX, ultimately you want to be invoking the TIOCGWINSZ (Get WINdow SiZe) ioctl() call. Most languages ought to have some sort of wrapper for that. E.g in Perl you can use Term::Size:

use Term::Size qw( chars );

my ( $columns, $rows ) = chars \*STDOUT;

git push: permission denied (public key)

None of the above solutions worked for me. For context, I'm running ubuntu, and I had already gone through the ssh-key setup documentation. The fix for me was to run ssh-add in the terminal. This fixed the issue.

Source: http://baptiste-wicht.com/posts/2010/07/tip-how-to-solve-agent-admitted-failure-to-sign-using-the-key-error.html

R barplot Y-axis scale too short

I see you try to set ylim but you give bad values. This will change the scale of the plot (like a zoom). For example see this:

par(mfrow=c(2,1))
tN <- table(Ni <- stats::rpois(100, lambda = 5))
r <- barplot(tN, col = rainbow(20),ylim=c(0,50),main='long y-axis')
r <- barplot(tN, col = rainbow(20),main='short y axis')

enter image description here Another option is to plot without axes and set them manually using axis and usr:

require(grDevices) # for colours
par(mfrow=c(1,1))
r <- barplot(tN, col = rainbow(20),main='short y axis',ann=FALSE,axes=FALSE)
usr <- par("usr")
par(usr=c(usr[1:2], 0, 20))
axis(2,at=seq(0,20,5))

enter image description here

Add new item in existing array in c#.net

I agree with Ed. C# does not make this easy the way VB does with ReDim Preserve. Without a collection, you'll have to copy the array into a larger one.

WARNING: Setting property 'source' to 'org.eclipse.jst.jee.server:appname' did not find a matching property

Despite this question being rather old, I had to deal with a similar warning and wanted to share what I found out.

First of all this is a warning and not an error. So there is no need to worry too much about it. Basically it means, that Tomcat does not know what to do with the source attribute from context.

This source attribute is set by Eclipse (or to be more specific the Eclipse Web Tools Platform) to the server.xml file of Tomcat to match the running application to a project in workspace.

Tomcat generates a warning for every unknown markup in the server.xml (i.e. the source attribute) and this is the source of the warning. You can safely ignore it.

How to force a SQL Server 2008 database to go Offline

You need to use WITH ROLLBACK IMMEDIATE to boot other conections out with no regards to what or who is is already using it.

Or use WITH NO_WAIT to not hang and not kill existing connections. See http://www.blackwasp.co.uk/SQLOffline.aspx for details

Simplest way to merge ES6 Maps/Sets?

The approved answer is great but that creates a new set every time.

If you want to mutate an existing object instead, use a helper function.

Set

function concatSets(set, ...iterables) {
    for (const iterable of iterables) {
        for (const item of iterable) {
            set.add(item);
        }
    }
}

Usage:

const setA = new Set([1, 2, 3]);
const setB = new Set([4, 5, 6]);
const setC = new Set([7, 8, 9]);
concatSets(setA, setB, setC);
// setA will have items 1, 2, 3, 4, 5, 6, 7, 8, 9

Map

function concatMaps(map, ...iterables) {
    for (const iterable of iterables) {
        for (const item of iterable) {
            map.set(...item);
        }
    }
}

Usage:

const mapA = new Map().set('S', 1).set('P', 2);
const mapB = new Map().set('Q', 3).set('R', 4);
concatMaps(mapA, mapB);
// mapA will have items ['S', 1], ['P', 2], ['Q', 3], ['R', 4]

Any way to Invoke a private method?

Let me provide complete code for execution protected methods via reflection. It supports any types of params including generics, autoboxed params and null values

@SuppressWarnings("unchecked")
public static <T> T executeSuperMethod(Object instance, String methodName, Object... params) throws Exception {
    return executeMethod(instance.getClass().getSuperclass(), instance, methodName, params);
}

public static <T> T executeMethod(Object instance, String methodName, Object... params) throws Exception {
    return executeMethod(instance.getClass(), instance, methodName, params);
}

@SuppressWarnings("unchecked")
public static <T> T executeMethod(Class clazz, Object instance, String methodName, Object... params) throws Exception {

    Method[] allMethods = clazz.getDeclaredMethods();

    if (allMethods != null && allMethods.length > 0) {

        Class[] paramClasses = Arrays.stream(params).map(p -> p != null ? p.getClass() : null).toArray(Class[]::new);

        for (Method method : allMethods) {
            String currentMethodName = method.getName();
            if (!currentMethodName.equals(methodName)) {
                continue;
            }
            Type[] pTypes = method.getParameterTypes();
            if (pTypes.length == paramClasses.length) {
                boolean goodMethod = true;
                int i = 0;
                for (Type pType : pTypes) {
                    if (!ClassUtils.isAssignable(paramClasses[i++], (Class<?>) pType)) {
                        goodMethod = false;
                        break;
                    }
                }
                if (goodMethod) {
                    method.setAccessible(true);
                    return (T) method.invoke(instance, params);
                }
            }
        }

        throw new MethodNotFoundException("There are no methods found with name " + methodName + " and params " +
            Arrays.toString(paramClasses));
    }

    throw new MethodNotFoundException("There are no methods found with name " + methodName);
}

Method uses apache ClassUtils for checking compatibility of autoboxed params

ASP.NET Web API - PUT & DELETE Verbs Not Allowed - IIS 8

Enable CORS (nice and neat)

1.Add CORS nuget package

Install-Package microsoft.aspnet.webapi.cors

2.in the WebApiConfig.cs file to Register method add bellow code :

config.EnableCors();

ex:
using System.Web.Http;

namespace test
{
public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Web API configuration and services


        config.EnableCors(); //add this**************************


        // Web API routes
        config.MapHttpAttributeRoutes();

        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );           
    }
}
}

3.Add bellow code into namespace of the controller include get,post,delete,put or any http method

[EnableCors(origins: "The address from which the request comes", headers: "*", methods: "*")]

ex:

using System.Web.Http.Cors;//add this******************************
namespace Test.Controllers
{
[EnableCors(origins: "http://localhost:53681/HTML/Restaurant.html", headers: "*", methods: "*")]
public class RestaurantController : ApiController
{
    protected TestBusinessLayer DevTestBLL = new TestBusinessLayer();

    public List<Restaurant> GET()
    {
        return DevTestBLL.GetRestaurant();
    }

    public List<Restaurant> DELETE(int id)
    {
        return DevTestBLL.DeleteRestaurant(id);
    }       
}
}

reference :http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api

How to get the correct range to set the value to a cell?

Solution : SpreadsheetApp.getActiveSheet().getRange('F2').setValue('hello')

Explanation :

Setting value in a cell in spreadsheet to which script is attached

SpreadsheetApp.getActiveSpreadsheet().getSheetByName(SHEET_NAME).getRange(RANGE).setValue(VALUE);

Setting value in a cell in sheet which is open currently and to which script is attached

SpreadsheetApp.getActiveSpreadsheet().getActiveSheet().getRange(RANGE).setValue(VALUE);

Setting value in a cell in some spreadsheet to which script is NOT attached (Destination sheet name known)

SpreadsheetApp.openById(SHEET_ID).getSheetByName(SHEET_NAME).getRange(RANGE).setValue(VALUE);

Setting value in a cell in some spreadsheet to which script is NOT attached (Destination sheet position known)

SpreadsheetApp.openById(SHEET_ID).getSheets()[POSITION].getRange(RANGE).setValue(VALUE);

These are constants, you must define them yourself

SHEET_ID

SHEET_NAME

POSITION

VALUE

RANGE

By script attached to a sheet I mean that script is residing in the script editor of that sheet. Not attached means not residing in the script editor of that sheet. It can be in any other place.

What is the difference between an interface and abstract class?

Let's work on this question again:

The first thing to let you know is that 1/1 and 1*1 results in the same, but it does not mean that multiplication and division are same. Obviously, they hold some good relationship, but mind you both are different.

I will point out main differences, and the rest have already been explained:

Abstract classes are useful for modeling a class hierarchy. At first glance of any requirement, we are partially clear on what exactly is to be built, but we know what to build. And so your abstract classes are your base classes.

Interfaces are useful for letting other hierarchy or classes to know that what I am capable of doing. And when you say I am capable of something, you must have that capacity. Interfaces will mark it as compulsory for a class to implement the same functionalities.

Count the number of items in my array list

You want to count the number of itemids in your array. Simply use:

int counter=list.size();

Less code increases efficiency. Do not re-invent the wheel...

A table name as a variable

Change your last statement to this:

EXEC('SELECT * FROM ' + @tablename)

This is how I do mine in a stored procedure. The first block will declare the variable, and set the table name based on the current year and month name, in this case TEST_2012OCTOBER. I then check if it exists in the database already, and remove if it does. Then the next block will use a SELECT INTO statement to create the table and populate it with records from another table with parameters.

--DECLARE TABLE NAME VARIABLE DYNAMICALLY
DECLARE @table_name varchar(max)
SET @table_name =
    (SELECT 'TEST_'
            + DATENAME(YEAR,GETDATE())
            + UPPER(DATENAME(MONTH,GETDATE())) )

--DROP THE TABLE IF IT ALREADY EXISTS
IF EXISTS(SELECT name
          FROM sysobjects
          WHERE name = @table_name AND xtype = 'U')

BEGIN
    EXEC('drop table ' +  @table_name)
END

--CREATES TABLE FROM DYNAMIC VARIABLE AND INSERTS ROWS FROM ANOTHER TABLE
EXEC('SELECT * INTO ' + @table_name + ' FROM dbo.MASTER WHERE STATUS_CD = ''A''')

How to display hidden characters by default (ZERO WIDTH SPACE ie. &#8203)

A very simple solution is to search your file(s) for non-ascii characters using a regular expression. This will nicely highlight all the spots where they are found with a border.

Search for [^\x00-\x7F] and check the box for Regex.

The result will look like this (in dark mode):

zero width space made visible

How should the ViewModel close the form?

This is probably very late, but I came across the same problem and I found a solution that works for me.

I can't figure out how to create an app without dialogs(maybe it's just a mind block). So I was at an impasse with MVVM and showing a dialog. So I came across this CodeProject article:

http://www.codeproject.com/KB/WPF/XAMLDialog.aspx

Which is a UserControl that basically allows a window to be within the visual tree of another window(not allowed in xaml). It also exposes a boolean DependencyProperty called IsShowing.

You can set a style like,typically in a resourcedictionary, that basically displays the dialog whenever the Content property of the control != null via triggers:

<Style TargetType="{x:Type d:Dialog}">
    <Style.Triggers>
        <Trigger Property="HasContent"  Value="True">
            <Setter Property="Showing" Value="True" />
        </Trigger>
    </Style.Triggers>
</Style>

In the view where you want to display the dialog simply have this:

<d:Dialog Content="{Binding Path=DialogViewModel}"/>

And in your ViewModel all you have to do is set the property to a value(Note: the ViewModel class must support INotifyPropertyChanged for the view to know something happened ).

like so:

DialogViewModel = new DisplayViewModel();

To match the ViewModel with the View you should have something like this in a resourcedictionary:

<DataTemplate DataType="{x:Type vm:DisplayViewModel}">
    <vw:DisplayView/>
</DataTemplate>

With all of that you get a one-liner code to show dialog. The problem you get is you can't really close the dialog with just the above code. So that's why you have to put in an event in a ViewModel base class which DisplayViewModel inherits from and instead of the code above, write this

        var vm = new DisplayViewModel();
        vm.RequestClose += new RequestCloseHandler(DisplayViewModel_RequestClose);
        DialogViewModel = vm;

Then you can handle the result of the dialog via the callback.

This may seem a little complex, but once the groundwork is laid, it's pretty straightforward. Again this is my implementation, I'm sure there are others :)

Hope this helps, it saved me.

How do I create and read a value from cookie?

I use this object. Values are encoded, so it's necessary to consider it when reading or writing from server side.

cookie = (function() {

/**
 * Sets a cookie value. seconds parameter is optional
 */
var set = function(name, value, seconds) {
    var expires = seconds ? '; expires=' + new Date(new Date().getTime() + seconds * 1000).toGMTString() : '';
    document.cookie = name + '=' + encodeURIComponent(value) + expires + '; path=/';
};

var map = function() {
    var map = {};
    var kvs = document.cookie.split('; ');
    for (var i = 0; i < kvs.length; i++) {
        var kv = kvs[i].split('=');
        map[kv[0]] = decodeURIComponent(kv[1]);
    }
    return map;
};

var get = function(name) {
    return map()[name];
};

var remove = function(name) {
    set(name, '', -1);
};

return {
    set: set,
    get: get,
    remove: remove,
    map: map
};

})();

How do I call paint event?

Maybe this is an old question and that´s the reason why these answers didn't work for me ... using Visual Studio 2019, after some investigating, this is the solution I've found:

this.InvokePaint(this, new PaintEventArgs(this.CreateGraphics(), this.DisplayRectangle));

Use of document.getElementById in JavaScript

You're correct in that the document.getElementById("demo") call gets you the element by the specified ID. But you have to look at the rest of the statement to figure out what exactly the code is doing with that element:

.innerHTML=voteable;

You can see here that it's setting the innerHTML of that element to the value of voteable.

What are the calling conventions for UNIX & Linux system calls (and user-space functions) on i386 and x86-64

Perhaps you're looking for the x86_64 ABI?

If that's not precisely what you're after, use 'x86_64 abi' in your preferred search engine to find alternative references.

Sending credentials with cross-domain posts?

In jQuery 3 and perhaps earlier versions, the following simpler config also works for individual requests:

$.ajax(
        'https://foo.bar.com,
        {
            dataType: 'json',
            xhrFields: {
                withCredentials: true
            },
            success: successFunc
        }
    );

The full error I was getting in Firefox Dev Tools -> Network tab (in the Security tab for an individual request) was:

An error occurred during a connection to foo.bar.com.SSL peer was unable to negotiate an acceptable set of security parameters.Error code: SSL_ERROR_HANDSHAKE_FAILURE_ALERT

PHP mySQL - Insert new record into table with auto-increment on primary key

You can also use blank single quotes for the auto_increment column. something like this. It worked for me.

$query = "INSERT INTO myTable VALUES ('','Fname', 'Lname', 'Website')";

Undefined reference to 'vtable for xxx'

You may take a look at this answer to an identical question (as I understand): https://stackoverflow.com/a/1478553 The link posted there explains the problem.

For quick solving your problem you should try to code something like this:

ImplementingClass::virtualFunctionToImplement(){...} It helped me a lot.

How to deal with floating point number precision in JavaScript?

Solved it by first making both numbers integers, executing the expression and afterwards dividing the result to get the decimal places back:

function evalMathematicalExpression(a, b, op) {
    const smallest = String(a < b ? a : b);
    const factor = smallest.length - smallest.indexOf('.');

    for (let i = 0; i < factor; i++) {
        b *= 10;
        a *= 10;
    }

    a = Math.round(a);
    b = Math.round(b);
    const m = 10 ** factor;
    switch (op) {
        case '+':
            return (a + b) / m;
        case '-':
            return (a - b) / m;
        case '*':
            return (a * b) / (m ** 2);
        case '/':
            return a / b;
    }

    throw `Unknown operator ${op}`;
}

Results for several operations (the excluded numbers are results from eval):

0.1 + 0.002   = 0.102 (0.10200000000000001)
53 + 1000     = 1053 (1053)
0.1 - 0.3     = -0.2 (-0.19999999999999998)
53 - -1000    = 1053 (1053)
0.3 * 0.0003  = 0.00009 (0.00008999999999999999)
100 * 25      = 2500 (2500)
0.9 / 0.03    = 30 (30.000000000000004)
100 / 50      = 2 (2)

Validate a username and password against Active Directory?

Try this code (NOTE: Reported to not work on windows server 2000)

#region NTLogonUser
#region Direct OS LogonUser Code
[DllImport( "advapi32.dll")]
private static extern bool LogonUser(String lpszUsername, 
    String lpszDomain, String lpszPassword, int dwLogonType, 
    int dwLogonProvider, out int phToken);

[DllImport("Kernel32.dll")]
private static extern int GetLastError();

public static bool LogOnXP(String sDomain, String sUser, String sPassword)
{
   int token1, ret;
   int attmpts = 0;

   bool LoggedOn = false;

   while (!LoggedOn && attmpts < 2)
   {
      LoggedOn= LogonUser(sUser, sDomain, sPassword, 3, 0, out token1);
      if (LoggedOn) return (true);
      else
      {
         switch (ret = GetLastError())
         {
            case (126): ; 
               if (attmpts++ > 2)
                  throw new LogonException(
                      "Specified module could not be found. error code: " + 
                      ret.ToString());
               break;

            case (1314): 
               throw new LogonException(
                  "Specified module could not be found. error code: " + 
                      ret.ToString());

            case (1326): 
               // edited out based on comment
               //  throw new LogonException(
               //   "Unknown user name or bad password.");
            return false;

            default: 
               throw new LogonException(
                  "Unexpected Logon Failure. Contact Administrator");
              }
          }
       }
   return(false);
}
#endregion Direct Logon Code
#endregion NTLogonUser

except you'll need to create your own custom exception for "LogonException"

How to pass an array within a query string?

Check the parse_string function http://php.net/manual/en/function.parse-str.php

It will return all the variables from a query string, including arrays.

Example from php.net:

<?php
$str = "first=value&arr[]=foo+bar&arr[]=baz";
parse_str($str);
echo $first;  // value
echo $arr[0]; // foo bar
echo $arr[1]; // baz

parse_str($str, $output);
echo $output['first'];  // value
echo $output['arr'][0]; // foo bar
echo $output['arr'][1]; // baz

?>

How to get and set the current web page scroll position?

There are some inconsistencies in how browsers expose the current window scrolling coordinates. Google Chrome on Mac and iOS seems to always return 0 when using document.documentElement.scrollTop or jQuery's $(window).scrollTop().

However, it works consistently with:

// horizontal scrolling amount
window.pageXOffset

// vertical scrolling amount
window.pageYOffset

Is there a performance difference between CTE , Sub-Query, Temporary Table or Table Variable?

#temp is materalized and CTE is not.

CTE is just syntax so in theory it is just a subquery. It is executed. #temp is materialized. So an expensive CTE in a join that is execute many times may be better in a #temp. On the other side if it is an easy evaluation that is not executed but a few times then not worth the overhead of #temp.

The are some people on SO that don't like table variable but I like them as the are materialized and faster to create than #temp. There are times when the query optimizer does better with a #temp compared to a table variable.

The ability to create a PK on a #temp or table variable gives the query optimizer more information than a CTE (as you cannot declare a PK on a CTE).

how to remove pagination in datatable

You should include "bPaginate": false, into the configuration object you pass to your constructor parameters. As seen here: http://datatables.net/release-datatables/examples/basic_init/filter_only.html

Python: Figure out local timezone

The following appears to work for 3.7+, using standard libs:

from datetime import timedelta
from datetime import timezone
import time

def currenttz():
    if time.daylight:
        return timezone(timedelta(seconds=-time.altzone),time.tzname[1])
    else:
        return timezone(timedelta(seconds=-time.timezone),time.tzname[0])

How to change the text of a label?

try this

$("label").html(your value); or $("label").text(your value);

Multiple inputs with same name through POST in php

It can be:

echo "Welcome".$_POST['firstname'].$_POST['lastname'];

Component based game engine design

It is open-source, and available at http://codeplex.com/elephant

Some one’s made a working example of the gpg6-code, you can find it here: http://www.unseen-academy.de/componentSystem.html

or here: http://www.mcshaffry.com/GameCode/thread.php?threadid=732

regards

How can I change the default Mysql connection timeout when connecting through python?

MAX_EXECUTION_TIME is also an important parameter for long running queries.Will work for MySQL 5.7 or later.

Check the current value

SELECT @@GLOBAL.MAX_EXECUTION_TIME, @@SESSION.MAX_EXECUTION_TIME;

Then set it according to your needs.

SET SESSION MAX_EXECUTION_TIME=2000;
SET GLOBAL MAX_EXECUTION_TIME=2000;

Server http:/localhost:8080 requires a user name and a password. The server says: XDB

Open the file :

WEB-INF -> web.xml

In my case, it looks like as following. :

<security-constraint>
    <web-resource-collection>
        <web-resource-name>Integration Web Services</web-resource-name>
        <description>Integration Web Services accessible by authorized users</description>
        <url-pattern>/services/*</url-pattern>
        <http-method>GET</http-method>
        <http-method>POST</http-method>
    </web-resource-collection>
    <auth-constraint>
        <description>Roles that have access to Integration Web Services</description>
        <role-name>maximouser</role-name>
    </auth-constraint>
    <user-data-constraint>
        <description>Data Transmission Guarantee</description>
        <transport-guarantee>NONE</transport-guarantee>
    </user-data-constraint>
</security-constraint>

Remove or comment these lines.

JQuery/Javascript: check if var exists

Before each of your conditional statements, you could do something like this:

var pagetype = pagetype || false;
if (pagetype === 'something') {
    //do stuff
}

Disable submit button ONLY after submit

Reading the comments, it seems that these solutions are not consistent across browsers. Decided then to think how I would have done this 10 years ago before the advent of jQuery and event function binding.

So here is my retro hipster solution:

<script type="text/javascript">
var _formConfirm_submitted = false;
</script>
<form name="frmConfirm" onsubmit="if( _formConfirm_submitted == false ){ _formConfirm_submitted = true;return true }else{ alert('your request is being processed!'); return false;  }" action="" method="GET">

<input type="submit" value="submit - but only once!"/>
</form>

The main point of difference is that I am relying on the ability to stop a form submitting through returning false on the submit handler, and I am using a global flag variable - which will make me go straight to hell!

But on the plus side, I cannot imagine any browser compatibility issues - hey, it would probably even work in Netscape!

C error: undefined reference to function, but it IS defined

How are you doing the compiling and linking? You'll need to specify both files, something like:

gcc testpoint.c point.c

...so that it knows to link the functions from both together. With the code as it's written right now, however, you'll then run into the opposite problem: multiple definitions of main. You'll need/want to eliminate one (undoubtedly the one in point.c).

In a larger program, you typically compile and link separately to avoid re-compiling anything that hasn't changed. You normally specify what needs to be done via a makefile, and use make to do the work. In this case you'd have something like this:

OBJS=testpoint.o point.o

testpoint.exe: $(OBJS)
    gcc $(OJBS)

The first is just a macro for the names of the object files. You get it expanded with $(OBJS). The second is a rule to tell make 1) that the executable depends on the object files, and 2) telling it how to create the executable when/if it's out of date compared to an object file.

Most versions of make (including the one in MinGW I'm pretty sure) have a built-in "implicit rule" to tell them how to create an object file from a C source file. It normally looks roughly like this:

.c.o:
    $(CC) -c $(CFLAGS) $<

This assumes the name of the C compiler is in a macro named CC (implicitly defined like CC=gcc) and allows you to specify any flags you care about in a macro named CFLAGS (e.g., CFLAGS=-O3 to turn on optimization) and $< is a special macro that expands to the name of the source file.

You typically store this in a file named Makefile, and to build your program, you just type make at the command line. It implicitly looks for a file named Makefile, and runs whatever rules it contains.

The good point of this is that make automatically looks at the timestamps on the files, so it will only re-compile the files that have changed since the last time you compiled them (i.e., files where the ".c" file has a more recent time-stamp than the matching ".o" file).

Also note that 1) there are lots of variations in how to use make when it comes to large projects, and 2) there are also lots of alternatives to make. I've only hit on the bare minimum of high points here.

How to create a folder with name as current date in batch (.bat) files

G:

cd G:/app/

mkdir %date:~7,2%%date:~-10,2%%date:~-4,4% 

cd %date:~7,2%%date:~-10,2%%date:~-4,4% 

sqlplus sys/sys as sysdba @c:/new

biggest integer that can be stored in a double

9007199254740992 (that's 9,007,199,254,740,992) with no guarantees :)

Program

#include <math.h>
#include <stdio.h>

int main(void) {
  double dbl = 0; /* I started with 9007199254000000, a little less than 2^53 */
  while (dbl + 1 != dbl) dbl++;
  printf("%.0f\n", dbl - 1);
  printf("%.0f\n", dbl);
  printf("%.0f\n", dbl + 1);
  return 0;
}

Result

9007199254740991
9007199254740992
9007199254740992

Responsive Images with CSS

check the images first with php if it is small then the standerd size for logo provide it any other css class and dont change its size

i think you have to take up scripting in between

HTML colspan in CSS

To provide an up-to-date answer: The best way to do this today is to use css grid layout like this:

.container {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-template-rows: auto;
  grid-template-areas: 
    "top-left top-middle top-right"
    "bottom bottom bottom"
}

.item-a {
  grid-area: top-left;
}
.item-b {
  grid-area: top-middle;
}
.item-c {
  grid-area: top-right;
}
.item-d {
  grid-area: bottom;
}

and the HTML

<div class="container">
  <div class="item-a">1</div>
  <div class="item-b">2</div>
  <div class="item-c">3</div>
  <div class="item-d">123</div>
</div>

Convert a number to 2 decimal places in Java

DecimalFormat df=new DecimalFormat("0.00");

Use this code to get exact two decimal points. Even if the value is 0.0 it will give u 0.00 as output.

Instead if you use:

DecimalFormat df=new DecimalFormat("#.00");  

It wont convert 0.2659 into 0.27. You will get an answer like .27.

adding .css file to ejs

In order to serve up a static CSS file in express app (i.e. use a css style file to style ejs "templates" files in express app). Here are the simple 3 steps that need to happen:

  1. Place your css file called "styles.css" in a folder called "assets" and the assets folder in a folder called "public". Thus the relative path to the css file should be "/public/assets/styles.css"

  2. In the head of each of your ejs files you would simply call the css file (like you do in a regular html file) with a <link href=… /> as shown in the code below. Make sure you copy and paste the code below directly into your ejs file <head> section

    <link href= "/public/assets/styles.css" rel="stylesheet" type="text/css" />
    
  3. In your server.js file, you need to use the app.use() middleware. Note that a middleware is nothing but a term that refers to those operations or code that is run between the request and the response operations. By putting a method in middleware, that method will automatically be called everytime between the request and response methods. To serve up static files (such as a css file) in the app.use() middleware there is already a function/method provided by express called express.static(). Lastly, you also need to specify a request route that the program will respond to and serve up the files from the static folder everytime the middleware is called. Since you will be placing the css files in your public folder. In the server.js file, make sure you have the following code:

    // using app.use to serve up static CSS files in public/assets/ folder when /public link is called in ejs files
    // app.use("/route", express.static("foldername"));
    app.use('/public', express.static('public'));
    

After following these simple 3 steps, every time you res.render('ejsfile') in your app.get() methods you will automatically see the css styling being called. You can test by accessing your routes in the browser.

Execute and get the output of a shell command in node.js

You can use the util library that comes with nodejs to get a promise from the exec command and can use that output as you need. Use restructuring to store the stdout and stderr in variables.

_x000D_
_x000D_
const util = require('util');
const exec = util.promisify(require('child_process').exec);

async function lsExample() {
  const {
    stdout,
    stderr
  } = await exec('ls');
  console.log('stdout:', stdout);
  console.error('stderr:', stderr);
}
lsExample();
_x000D_
_x000D_
_x000D_

DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled

On Windows 10,

I just solved this issue by doing the following.

  1. Goto my.ini and add these 2 lines under [mysqld]

    skip-log-bin
    log_bin_trust_function_creators = 1
    
  2. restart MySQL service

failed to push some refs to [email protected]

Execute this:

$ rake assets:precompile
$ git add .
$ git commit -m "Add precompiled assets for Heroku"
$ git push heroku master

Source: http://ruby.railstutorial.org/ruby-on-rails-tutorial-book

Python Requests library redirect new url

For python3.5, you can use the following code:

import urllib.request
res = urllib.request.urlopen(starturl)
finalurl = res.geturl()
print(finalurl)

jQuery checkbox change and click event

Here you are

Html

<input id="ProductId_a183060c-1030-4037-ae57-0015be92da0e" type="checkbox" value="true">

JavaScript

<script>
    $(document).ready(function () {

      $('input[id^="ProductId_"]').click(function () {

        if ($(this).prop('checked')) {
           // do what you need here     
           alert("Checked");
        }
        else {
           // do what you need here         
           alert("Unchecked");
        }
      });

  });
</script>

Powershell Invoke-WebRequest Fails with SSL/TLS Secure Channel

It works for me...

if (-not ([System.Management.Automation.PSTypeName]'ServerCertificateValidationCallback').Type)
    {
    $certCallback = @"
        using System;
        using System.Net;
        using System.Net.Security;
        using System.Security.Cryptography.X509Certificates;
        public class ServerCertificateValidationCallback
        {
            public static void Ignore()
            {
                if(ServicePointManager.ServerCertificateValidationCallback ==null)
                {
                    ServicePointManager.ServerCertificateValidationCallback += 
                        delegate
                        (
                            Object obj, 
                            X509Certificate certificate, 
                            X509Chain chain, 
                            SslPolicyErrors errors
                        )
                        {
                            return true;
                        };
                }
            }
        }
    "@
        Add-Type $certCallback
     }
    [ServerCertificateValidationCallback]::Ignore()

Invoke-WebRequest -Uri https://apod.nasa.gov/apod/

Go to "next" iteration in JavaScript forEach loop

just return true inside your if statement

var myArr = [1,2,3,4];

myArr.forEach(function(elem){
  if (elem === 3) {

      return true;

    // Go to "next" iteration. Or "continue" to next iteration...
  }

  console.log(elem);
});

Javascript change color of text and background to input value

Depending on which event you actually want to use (textbox change, or button click), you can try this:

HTML:

<input id="color" type="text" onchange="changeBackground(this);" />
<br />
<span id="coltext">This text should have the same color as you put in the text box</span>

JS:

function changeBackground(obj) {
    document.getElementById("coltext").style.color = obj.value;
}

DEMO: http://jsfiddle.net/6pLUh/

One minor problem with the button was that it was a submit button, in a form. When clicked, that submits the form (which ends up just reloading the page) and any changes from JavaScript are reset. Just using the onchange allows you to change the color based on the input.

addID in jQuery?

I've used something like this before which addresses @scunliffes concern. It finds all instances of items with a class of (in this case .button), and assigns an ID and appends its index to the id name:

_x000D_
_x000D_
$(".button").attr('id', function (index) {_x000D_
 return "button-" + index;_x000D_
});
_x000D_
_x000D_
_x000D_

So let's say you have 3 items with the class name of .button on a page. The result would be adding a unique ID to all of them (in addition to their class of "button").

In this case, #button-0, #button-1, #button-2, respectively. This can come in very handy. Simply replace ".button" in the first line with whatever class you want to target, and replace "button" in the return statement with whatever you'd like your unique ID to be. Hope this helps!

Slide up/down effect with ng-show and ng-animate

What's wrong with actually using ng-animate for ng-show as you mentioned?

<script src="lib/angulr.js"></script>
<script src="lib/angulr_animate.js"></script>
<script>
    var app=angular.module('ang_app', ['ngAnimate']);
    app.controller('ang_control01_main', function($scope) {

    });
</script>
<style>
    #myDiv {
        transition: .5s;
        background-color: lightblue;
        height: 100px;
    }
    #myDiv.ng-hide {
        height: 0;
    }
</style>
<body ng-app="ang_app" ng-controller="ang_control01_main">
    <input type="checkbox" ng-model="myCheck">
    <div id="myDiv" ng-show="myCheck"></div>
</body>

JAVA_HOME directory in Linux

On Linux you can run $(dirname $(dirname $(readlink -f $(which javac))))

On Mac you can run $(dirname $(readlink $(which javac)))/java_home

I'm not sure about windows but I imagine where javac would get you pretty close

Fill Combobox from database

            SqlConnection conn = new SqlConnection(@"Data Source=TOM-PC\sqlexpress;Initial Catalog=Northwind;User ID=sa;Password=xyz") ;
            conn.Open();
            SqlCommand sc = new SqlCommand("select customerid,contactname from customers", conn);
            SqlDataReader reader;

            reader = sc.ExecuteReader();
            DataTable dt = new DataTable();
            dt.Columns.Add("customerid", typeof(string));
            dt.Columns.Add("contactname", typeof(string));
            dt.Load(reader);

            comboBox1.ValueMember = "customerid";
            comboBox1.DisplayMember = "contactname";
            comboBox1.DataSource = dt;

            conn.Close();

Return index of greatest value in an array

Another solution of max using reduce:

[1,2,5,0,4].reduce((a,b,i) => a[0] < b ? [b,i] : a, [Number.MIN_VALUE,-1])
//[5,2]

This returns [5e-324, -1] if the array is empty. If you want just the index, put [1] after.

Min via (Change to > and MAX_VALUE):

[1,2,5,0,4].reduce((a,b,i) => a[0] > b ? [b,i] : a, [Number.MAX_VALUE,-1])
//[0, 3]

How do I debug Windows services in Visual Studio?

Use the following code in service OnStart method:

System.Diagnostics.Debugger.Launch();

Choose the Visual Studio option from the pop up message.

Note: To use it in only Debug mode, a #if DEBUG compiler directive can be used, as follows. This will prevent accidental or debugging in release mode on a production server.

#if DEBUG
    System.Diagnostics.Debugger.Launch();
#endif

Running a cron job at 2:30 AM everyday

As seen in the other answers, the syntax to use is:

  30 2 * * * /your/command
# ^  ^
# |   hour
# minute

Following the crontab standard format:

 +---------------- minute (0 - 59)
 |  +------------- hour (0 - 23)
 |  |  +---------- day of month (1 - 31)
 |  |  |  +------- month (1 - 12)
 |  |  |  |  +---- day of week (0 - 6) (Sunday=0 or 7)
 |  |  |  |  |
 *  *  *  *  *  command to be executed

It is also useful to use crontab.guru to check crontab expressions.

The expressions are added into crontab using crontab -e. Once you are done, save and exit (if you are using vi, typing :x does it). The good think of using this tool is that if you write an invalid command you are likely to get a message prompt on the form:

$ crontab -e
crontab: installing new crontab
"/tmp/crontab.tNt1NL/crontab":7: bad minute
errors in crontab file, can't install.
Do you want to retry the same edit? (y/n) 

If you have further problems with crontab not running you can check Debugging crontab or Why is crontab not executing my PHP script?.

How to select an element inside "this" in jQuery?

$( this ).find( 'li.target' ).css("border", "3px double red");

or

$( this ).children( 'li.target' ).css("border", "3px double red");

Use children for immediate descendants, or find for deeper elements.

long long int vs. long int vs. int64_t in C++

So my question is: Is there a way to tell the compiler that a long long int is the also a int64_t, just like long int is?

This is a good question or problem, but I suspect the answer is NO.

Also, a long int may not be a long long int.


# if __WORDSIZE == 64
typedef long int  int64_t;
# else
__extension__
typedef long long int  int64_t;
# endif

I believe this is libc. I suspect you want to go deeper.

In both 32-bit compile with GCC (and with 32- and 64-bit MSVC), the output of the program will be:

int:           0
int64_t:       1
long int:      0
long long int: 1

32-bit Linux uses the ILP32 data model. Integers, longs and pointers are 32-bit. The 64-bit type is a long long.

Microsoft documents the ranges at Data Type Ranges. The say the long long is equivalent to __int64.

However, the program resulting from a 64-bit GCC compile will output:

int:           0
int64_t:       1
long int:      1
long long int: 0

64-bit Linux uses the LP64 data model. Longs are 64-bit and long long are 64-bit. As with 32-bit, Microsoft documents the ranges at Data Type Ranges and long long is still __int64.

There's a ILP64 data model where everything is 64-bit. You have to do some extra work to get a definition for your word32 type. Also see papers like 64-Bit Programming Models: Why LP64?


But this is horribly hackish and does not scale well (actual functions of substance, uint64_t, etc)...

Yeah, it gets even better. GCC mixes and matches declarations that are supposed to take 64 bit types, so its easy to get into trouble even though you follow a particular data model. For example, the following causes a compile error and tells you to use -fpermissive:

#if __LP64__
typedef unsigned long word64;
#else
typedef unsigned long long word64;
#endif

// intel definition of rdrand64_step (http://software.intel.com/en-us/node/523864)
// extern int _rdrand64_step(unsigned __int64 *random_val);

// Try it:
word64 val;
int res = rdrand64_step(&val);

It results in:

error: invalid conversion from `word64* {aka long unsigned int*}' to `long long unsigned int*'

So, ignore LP64 and change it to:

typedef unsigned long long word64;

Then, wander over to a 64-bit ARM IoT gadget that defines LP64 and use NEON:

error: invalid conversion from `word64* {aka long long unsigned int*}' to `uint64_t*'

What are the alternatives now that the Google web search API has been deprecated?

Here is an option at the bottom of the Custom Search Control Panel: "Sites to search", you can choose "Search the entire web but emphasize included sites"

Custom Search Control Panel - Sites to search

Make Bootstrap's Carousel both center AND responsive?

This work for me very simple just add attribute align="center". Tested on Bootstrap 4.

<!-- The slideshow -->
            <div class="carousel-inner" align="center">             
                <div class="carousel-item active">
                    <img src="image1.jpg" alt="no image" height="550">
                </div>
                <div class="carousel-item">
                    <img src="image2.jpg" alt="no image" height="550">
                </div>                
                <div class="carousel-item">
                    <img src="image3.png" alt="no image" height="550">
                </div>
             </div>

Entity Framework and SQL Server View

To get a view I had to only show one primary key column I created a second view that pointed to the first and used NULLIF to make the types nullable. This worked for me to make the EF think there was just a single primary key in the view.

Not sure if this will help you though since I don't believe the EF will accept an entity with NO primary key.

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.6 or one of its dependencies could not be resolved

Step1: Delete all instances of java from you machine

Step2: Delete all the environment variables related to java/jdk/jre

Step3: Check in programm files and program files(X86) folder, there should not be java folder.

Step4: Install java again.

Step5: Go to cmd and type "java -version" Result: it will display the java version which is installed in your machine.

Step6: now delete all the files which are in C:/User/AdminOrUserNameofYourMachine/.m2 folder

Step6: go to cmd and run "mvn -v" Result: It will display the Apache maven version installed on your machine

Step7: Now Rebuild your project.

This worked for me.

Declaring variables in Excel Cells

You can name cells. This is done by clicking the Name Box (that thing next to the formula bar which says "A1" for example) and typing a name, such as, "myvar". Now you can use that name instead of the cell reference:

= myvar*25

How to get file extension from string in C++

If you consider the extension as the last dot and the possible characters after it, but only if they don't contain the directory separator character, the following function returns the extension starting index, or -1 if no extension found. When you have that you can do what ever you want, like strip the extension, change it, check it etc.

long get_extension_index(string path, char dir_separator = '/') {
    // Look from the end for the first '.',
    // but give up if finding a dir separator char first
    for(long i = path.length() - 1; i >= 0; --i) {
        if(path[i] == '.') {
            return i;
        }
        if(path[i] == dir_separator) {
            return -1;
        }
    }
    return -1;
}

jQuery append and remove dynamic table row

Change ID to class :

$("#customFields").append('<tr valign="top"><th scope="row"><label for="customFieldName">Custom Field</label></th><td><input type="text" class="code" id="customFieldName" name="customFieldName[]" value="" placeholder="Input Name" /> &nbsp; <input type="text" class="code" id="customFieldValue" name="customFieldValue[]" value="" placeholder="Input Value" /> &nbsp; <a href="javascript:void(0);" class="remCF">Remove</a></td></tr>');

$(".remCF").on('click',function(){
            $(this).parent().parent().remove();
        });

http://jsfiddle.net/7BHDm/1/

What is a PDB file?

A PDB file contains information for the debugger to work with. There's less information in a Release build than in a Debug build anyway. But if you want it to not be generated at all, go to your project's Build properties, select the Release configuration, click on "Advanced..." and under "Debug Info" pick "None".

Function to close the window in Tkinter

class App():
    def __init__(self):
        self.root = Tkinter.Tk()
        button = Tkinter.Button(self.root, text = 'root quit', command=self.quit)
        button.pack()
        self.root.mainloop()

    def quit(self):
        self.root.destroy()

app = App()

How to quickly form groups (quartiles, deciles, etc) by ordering column(s) in a data frame

There's a handy ntile function in package dplyr. It's flexible in the sense that you can very easily define the number of *tiles or "bins" you want to create.

Load the package (install first if you haven't) and add the quartile column:

library(dplyr)
temp$quartile <- ntile(temp$value, 4)  

Or, if you want to use dplyr syntax:

temp <- temp %>% mutate(quartile = ntile(value, 4))

Result in both cases is:

temp
#   name       value quartile
#1     a -0.56047565        1
#2     b -0.23017749        2
#3     c  1.55870831        4
#4     d  0.07050839        2
#5     e  0.12928774        3
#6     f  1.71506499        4
#7     g  0.46091621        3
#8     h -1.26506123        1
#9     i -0.68685285        1
#10    j -0.44566197        2
#11    k  1.22408180        4
#12    l  0.35981383        3

data:

Note that you don't need to create the "quartile" column in advance and use set.seed to make the randomization reproducible:

set.seed(123)
temp <- data.frame(name=letters[1:12], value=rnorm(12))

How to delete a stash created with git stash create?

If you are 100% sure that you have just one stash or you want to delete all stashes (make a git stash list to be 107% sure), you can do a:

git stash clear

..and forget about them (it deletes all stashes).

Note: Added this answer for those who ended up here looking for a way to clear them all (like me).

What does the "More Columns than Column Names" error mean?

It uses commas as separators. So you can either set sep="," or just use read.csv:

x <- read.csv(file="http://www.irs.gov/file_source/pub/irs-soi/countyinflow1011.csv")
dim(x)
## [1] 113593      9

The error is caused by spaces in some of the values, and unmatched quotes. There are no spaces in the header, so read.table thinks that there is one column. Then it thinks it sees multiple columns in some of the rows. For example, the first two lines (header and first row):

State_Code_Dest,County_Code_Dest,State_Code_Origin,County_Code_Origin,State_Abbrv,County_Name,Return_Num,Exmpt_Num,Aggr_AGI
00,000,96,000,US,Total Mig - US & For,6973489,12948316,303495582

And unmatched quotes, for example on line 1336 (row 1335) which will confuse read.table with the default quote argument (but not read.csv):

01,089,24,033,MD,Prince George's County,13,30,1040

Getting number of days in a month

I made it calculate days in month from datetimepicker selected month and year , and I but the code in datetimepicker1 textchanged to return the result in a textbox with this code

private void DateTimePicker1_ValueChanged(object sender, EventArgs e)
{
    int s = System.DateTime.DaysInMonth(DateTimePicker1.Value.Date.Year, DateTimePicker1.Value.Date.Month);

    TextBox1.Text = s.ToString();
}