SyntaxFix.com - Programming Questions & Answers Hub For Beginners


Some Of The Best Answers From Latest Asked Questions

Header div stays at top, vertical scrolling div below with scrollbar only attached to that div

Here is a demo. Use position:fixed; top:0; left:0; so the header always stay on top.

?#header {
    background:red;
    height:50px;
    width:100%;
    position:fixed;
    top:0;
    left:0;    
}.scroller {
    height:300px; 
    overflow:scroll;    
}

How to sum data.frame column values?

You can just use sum(people$Weight).

sum sums up a vector, and people$Weight retrieves the weight column from your data frame.

Note - you can get built-in help by using ?sum, ?colSums, etc. (by the way, colSums will give you the sum for each column).

How do I return a proper success/error message for JQuery .ajax() using PHP?

...you may also want to check for cross site scripting issues...if your html pages comes from a different domain/port combi then your rest service, your browser may block the call.

Typically, right mouse->inspect on your html page. Then look in the error console for errors like

Access to XMLHttpRequest at '...:8080' from origin '...:8383' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Powershell Get-ChildItem most recent file in directory

You could try to sort descending "sort LastWriteTime -Descending" and then "select -first 1." Not sure which one is faster

Creating a segue programmatically

well , you can create and also can subclass the UIStoryBoardSegue . subclassing is mostly used for giving custom transition animation.

you can see video of wwdc 2011 introducing StoryBoard. its available in youtube also.

http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIStoryboardSegue_Class/Reference/Reference.html#//apple_ref/occ/cl/UIStoryboardSegue

AsyncTask Android example

When you are in the worker thread, you can not directly manipulate UI elements on Android.

When you are using AsyncTask please understand the callback methods.

For example:

public class MyAyncTask extends AsyncTask<Void, Void, Void>{

    @Override
    protected void onPreExecute() {
        // Here you can show progress bar or something on the similar lines.
        // Since you are in a UI thread here.
        super.onPreExecute();
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        // After completing execution of given task, control will return here.
        // Hence if you want to populate UI elements with fetched data, do it here.
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
        // You can track you progress update here
    }

    @Override
    protected Void doInBackground(Void... params) {
        // Here you are in the worker thread and you are not allowed to access UI thread from here.
        // Here you can perform network operations or any heavy operations you want.
        return null;
    }
}

FYI: To access the UI thread from a worker thread, you either use runOnUiThread() method or post method on your view.

For instance:

runOnUiThread(new Runnable() {
    textView.setText("something.");
});

or
    yourview.post(new Runnable() {
    yourview.setText("something");
});

This will help you know the things better. Hence in you case, you need to set your textview in the onPostExecute() method.

Split a python list into other "sublists" i.e smaller lists

chunks = [data[100*i:100*(i+1)] for i in range(len(data)/100 + 1)]

This is equivalent to the accepted answer. For example, shortening to batches of 10 for readability:

data = range(35)
print [data[x:x+10] for x in xrange(0, len(data), 10)]
print [data[10*i:10*(i+1)] for i in range(len(data)/10 + 1)]

Outputs:

[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12, 13, 14, 15, 16, 17, 18, 19], [20, 21, 22, 23, 24, 25, 26, 27, 28, 29], [30, 31, 32, 33, 34]]
[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12, 13, 14, 15, 16, 17, 18, 19], [20, 21, 22, 23, 24, 25, 26, 27, 28, 29], [30, 31, 32, 33, 34]]

How to display Oracle schema size with SQL query?

You probably want

SELECT sum(bytes)
  FROM dba_segments
 WHERE owner = <<owner of schema>>

If you are logged in as the schema owner, you can also

SELECT SUM(bytes)
  FROM user_segments

That will give you the space allocated to the objects owned by the user in whatever tablespaces they are in. There may be empty space allocated to the tables that is counted as allocated by these queries.

CSS vertical alignment of inline/inline-block elements

For fine tuning the position of an inline-block item, use top and left:

  position: relative;
  top: 5px;
  left: 5px;

Thanks CSS-Tricks!

CSS transition shorthand with multiple properties?

I think that this should work:

.element {
   -webkit-transition: all .3s;
   -moz-transition: all .3s;
   -o-transition: all .3s;
   transition: all .3s;
}

GUI Tool for PostgreSQL

Postgres Enterprise Manager from EnterpriseDB is probably the most advanced you'll find. It includes all the features of pgAdmin, plus monitoring of your hosts and database servers, predictive reporting, alerting and a SQL Profiler.

http://www.enterprisedb.com/products-services-training/products/postgres-enterprise-manager

Ninja edit disclaimer/notice: it seems that this user is affiliated with EnterpriseDB, as the linked Postgres Enterprise Manager website contains a video of one Dave Page.

How to update SQLAlchemy row entry?

There are several ways to UPDATE using sqlalchemy

1) user.no_of_logins += 1
   session.commit()

2) session.query().\
       filter(User.username == form.username.data).\
       update({"no_of_logins": (User.no_of_logins +1)})
   session.commit()

3) conn = engine.connect()
   stmt = User.update().\
       values(no_of_logins=(User.no_of_logins + 1)).\
       where(User.username == form.username.data)
   conn.execute(stmt)

4) setattr(user, 'no_of_logins', user.no_of_logins+1)
   session.commit()

Display PDF file inside my android application

Highly recommend you check out PDF.js which is able to render PDF documents in a standard a WebView component.

Also see https://github.com/loosemoose/androidpdf for a sample implementation of this.

How to delete multiple values from a vector?

There is also subset which might be useful sometimes:

a <- sample(1:10)
bad <- c(2, 3, 5)

> subset(a, !(a %in% bad))
[1]  9  7 10  6  8  1  4

How do I ignore all files in a folder with a Git repository in Sourcetree?

Right click on a file → IgnoreIgnore everything beneath.

If the Ignore option is grayed out then:

  1. Stage a file first
  2. Right click → Stop Tracking
  3. That file will appear in the pane below with a question mark → Right click on it→ Ignore

Enter image description here

C# : Passing a Generic Object

You're missing at least a couple of things:

  • Unless you're using reflection, the type arguments need to be known at compile-time, so you can't use

    PrintGeneric<test2.GetType()>
    

    ... although in this case you don't need to anyway

  • PrintGeneric doesn't know anything about T at the moment, so the compiler can't find a member called T

Options:

  • Put a property in the ITest interface, and change PrintGeneric to constrain T:

    public void PrintGeneric<T>(T test) where T : ITest
    {
        Console.WriteLine("Generic : " + test.PropertyFromInterface);
    }
    
  • Put a property in the ITest interface and remove the generics entirely:

    public void PrintGeneric(ITest test)
    {
        Console.WriteLine("Property : " + test.PropertyFromInterface);
    }
    
  • Use dynamic typing instead of generics if you're using C# 4

Best way to move files between S3 buckets?

For new version aws2.

aws2 s3 sync s3://SOURCE_BUCKET_NAME s3://NEW_BUCKET_NAME

Difference between application/x-javascript and text/javascript content types

mime-types starting with x- are not standardized. In case of javascript it's kind of outdated. Additional the second code snippet

<?Header('Content-Type: text/javascript');?>

requires short_open_tags to be enabled. you should avoid it.

<?php Header('Content-Type: text/javascript');?>

However, the completely correct mime-type for javascript is

application/javascript

http://www.iana.org/assignments/media-types/application/index.html

Retrieving an element from array list in Android?

Maybe the following helps you.

arraylistname.get(position);

java.lang.NoClassDefFoundError: org/apache/http/client/HttpClient

This problem occurs if there are different jar versions. Especially versions of httpcore and httpclient. Use same versions of httpcore and httpclient.

What is the difference between __init__ and __call__?

__init__ would be treated as Constructor where as __call__ methods can be called with objects any number of times. Both __init__ and __call__ functions do take default arguments.

Python code to remove HTML tags from a string

Using a regex

Using a regex, you can clean everything inside <> :

import re

def cleanhtml(raw_html):
  cleanr = re.compile('<.*?>')
  cleantext = re.sub(cleanr, '', raw_html)
  return cleantext

Some HTML texts can also contain entities that are not enclosed in brackets, such as '&nsbm'. If that is the case, then you might want to write the regex as

cleanr = re.compile('<.*?>|&([a-z0-9]+|#[0-9]{1,6}|#x[0-9a-f]{1,6});')

This link contains more details on this.

Using BeautifulSoup

You could also use BeautifulSoup additional package to find out all the raw text.

You will need to explicitly set a parser when calling BeautifulSoup I recommend "lxml" as mentioned in alternative answers (much more robust than the default one (html.parser) (i.e. available without additional install).

from bs4 import BeautifulSoup
cleantext = BeautifulSoup(raw_html, "lxml").text

But it doesn't prevent you from using external libraries, so I recommend the first solution.

EDIT: To use lxml you need to pip install lxml.

Override valueof() and toString() in Java enum

Try this, but i don't sure that will work every where :)

public enum MyEnum {
    A("Start There"),
    B("Start Here");

    MyEnum(String name) {
        try {
            Field fieldName = getClass().getSuperclass().getDeclaredField("name");
            fieldName.setAccessible(true);
            fieldName.set(this, name);
            fieldName.setAccessible(false);
        } catch (Exception e) {}
    }
}

Remove padding or margins from Google Charts

I arrived here like most people with this same issue, and left shocked that none of the answer even remotely worked.

For anyone interested, here is the actual solution:

... //rest of options
width: '100%',
height: '350',
chartArea:{
    left:5,
    top: 20,
    width: '100%',
    height: '350',
}
... //rest of options

The key here has nothing to do with the "left" or "top" values. But rather that the:

Dimensions of both the chart and chart-area are SET and set to the SAME VALUE

As an amendment to my answer. The above will indeed solve the "excessive" padding/margin/whitespace problem. However, if you wish to include axes labels and/or a legend you will need to reduce the height & width of the chart area so something slightly below the outer width/height. This will "tell" the chart API that there is sufficient room to display these properties. Otherwise it will happily exclude them.

How to get a tab character?

put it in between <pre></pre> tags then use this characters &#9;

it would not work without the <pre></pre> tags

Get a DataTable Columns DataType

dt.Columns[0].DataType.Name.ToString()

Installing Apple's Network Link Conditioner Tool

Update on the answer December 2019 Xcode 11.1.2

Apple has moved Network Link Conditioner Tool to additional tools for Xcode

Go to the below link

https://developer.apple.com/download/more/?q=Additional%20Tools

enter image description here

Install the dmg file, select hardware from installer

enter image description here

select Network Link conditioner prefpane enter image description here

Rails: select unique values from a column

If anyone is looking for the same with Mongoid, that is

Model.distinct(:rating)

Why can't I initialize non-const static member or static array in class?

Why I can't initialize static data members in class?

The C++ standard allows only static constant integral or enumeration types to be initialized inside the class. This is the reason a is allowed to be initialized while others are not.

Reference:
C++03 9.4.2 Static data members
§4

If a static data member is of const integral or const enumeration type, its declaration in the class definition can specify a constant-initializer which shall be an integral constant expression (5.19). In that case, the member can appear in integral constant expressions. The member shall still be defined in a namespace scope if it is used in the program and the namespace scope definition shall not contain an initializer.

What are integral types?

C++03 3.9.1 Fundamental types
§7

Types bool, char, wchar_t, and the signed and unsigned integer types are collectively called integral types.43) A synonym for integral type is integer type.

Footnote:

43) Therefore, enumerations (7.2) are not integral; however, enumerations can be promoted to int, unsigned int, long, or unsigned long, as specified in 4.5.

Workaround:

You could use the enum trick to initialize an array inside your class definition.

class A 
{
    static const int a = 3;
    enum { arrsize = 2 };

    static const int c[arrsize] = { 1, 2 };

};

Why does the Standard does not allow this?

Bjarne explains this aptly here:

A class is typically declared in a header file and a header file is typically included into many translation units. However, to avoid complicated linker rules, C++ requires that every object has a unique definition. That rule would be broken if C++ allowed in-class definition of entities that needed to be stored in memory as objects.

Why are only static const integral types & enums allowed In-class Initialization?

The answer is hidden in Bjarne's quote read it closely,
"C++ requires that every object has a unique definition. That rule would be broken if C++ allowed in-class definition of entities that needed to be stored in memory as objects."

Note that only static const integers can be treated as compile time constants. The compiler knows that the integer value will not change anytime and hence it can apply its own magic and apply optimizations, the compiler simply inlines such class members i.e, they are not stored in memory anymore, As the need of being stored in memory is removed, it gives such variables the exception to rule mentioned by Bjarne.

It is noteworthy to note here that even if static const integral values can have In-Class Initialization, taking address of such variables is not allowed. One can take the address of a static member if (and only if) it has an out-of-class definition.This further validates the reasoning above.

enums are allowed this because values of an enumerated type can be used where ints are expected.see citation above


How does this change in C++11?

C++11 relaxes the restriction to certain extent.

C++11 9.4.2 Static data members
§3

If a static data member is of const literal type, its declaration in the class definition can specify a brace-or-equal-initializer in which every initializer-clause that is an assignment-expression is a constant expression. A static data member of literal type can be declared in the class definition with the constexpr specifier; if so, its declaration shall specify a brace-or-equal-initializer in which every initializer-clause that is an assignment-expression is a constant expression. [ Note: In both these cases, the member may appear in constant expressions. —end note ] The member shall still be defined in a namespace scope if it is used in the program and the namespace scope definition shall not contain an initializer.

Also, C++11 will allow(§12.6.2.8) a non-static data member to be initialized where it is declared(in its class). This will mean much easy user semantics.

Note that these features have not yet been implemented in latest gcc 4.7, So you might still get compilation errors.

How to create a shortcut using PowerShell

I don't know any native cmdlet in powershell but you can use com object instead:

$WshShell = New-Object -comObject WScript.Shell
$Shortcut = $WshShell.CreateShortcut("$Home\Desktop\ColorPix.lnk")
$Shortcut.TargetPath = "C:\Program Files (x86)\ColorPix\ColorPix.exe"
$Shortcut.Save()

you can create a powershell script save as set-shortcut.ps1 in your $pwd

param ( [string]$SourceExe, [string]$DestinationPath )

$WshShell = New-Object -comObject WScript.Shell
$Shortcut = $WshShell.CreateShortcut($DestinationPath)
$Shortcut.TargetPath = $SourceExe
$Shortcut.Save()

and call it like this

Set-ShortCut "C:\Program Files (x86)\ColorPix\ColorPix.exe" "$Home\Desktop\ColorPix.lnk"

If you want to pass arguments to the target exe, it can be done by:

#Set the additional parameters for the shortcut  
$Shortcut.Arguments = "/argument=value"  

before $Shortcut.Save().

For convenience, here is a modified version of set-shortcut.ps1. It accepts arguments as its second parameter.

param ( [string]$SourceExe, [string]$ArgumentsToSourceExe, [string]$DestinationPath )
$WshShell = New-Object -comObject WScript.Shell
$Shortcut = $WshShell.CreateShortcut($DestinationPath)
$Shortcut.TargetPath = $SourceExe
$Shortcut.Arguments = $ArgumentsToSourceExe
$Shortcut.Save()

How to insert double and float values to sqlite?

SQL Supports following types of affinities:

  • TEXT
  • NUMERIC
  • INTEGER
  • REAL
  • BLOB

If the declared type for a column contains any of these "REAL", "FLOAT", or "DOUBLE" then the column has 'REAL' affinity.

Git - how delete file from remote repository

Visual Studio Code:

Delete the files from your Explorer view. You see them crossed-out in your Branch view. Then commit and Sync.

enter image description here

Be aware: If files are on your .gitignore list, then the delete "update" will not be pushed and therefore not be visible. VS Code will warn you if this is the case, though. -> Exclude the files/folder from gitignore temporarily.

What is difference between sleep() method and yield() method of multi threading?

sleep()causes the thread to definitely stop executing for a given amount of time; if no other thread or process needs to be run, the CPU will be idle (and probably enter a power saving mode). yield()basically means that the thread is not doing anything particularly important and if any other threads or processes need to be run, they should. Otherwise, the current thread will continue to run.

In Powershell what is the idiomatic way of converting a string to an int?

I'd probably do something like that :

[int]::Parse("35")

But I'm not really a Powershell guy. It uses the static Parse method from System.Int32. It should throw an exception if the string can't be parsed.

CMake complains "The CXX compiler identification is unknown"

Your /home/gnu/bin/c++ seem to require additional flag to link things properly and CMake doesn't know about that.

To use /usr/bin/c++ as your compiler run cmake with -DCMAKE_CXX_COMPILER=/usr/bin/c++.

Also, CMAKE_PREFIX_PATH variable sets destination dir where your project' files should be installed. It has nothing to do with CMake installation prefix and CMake itself already know this.

super() raises "TypeError: must be type, not classobj" for new-style class

The problem is that super needs an object as an ancestor:

>>> class oldstyle:
...     def __init__(self): self.os = True

>>> class myclass(oldstyle):
...     def __init__(self): super(myclass, self).__init__()

>>> myclass()
TypeError: must be type, not classobj

On closer examination one finds:

>>> type(myclass)
classobj

But:

>>> class newstyle(object): pass

>>> type(newstyle)
type    

So the solution to your problem would be to inherit from object as well as from HTMLParser. But make sure object comes last in the classes MRO:

>>> class myclass(oldstyle, object):
...     def __init__(self): super(myclass, self).__init__()

>>> myclass().os
True

How to use pip on windows behind an authenticating proxy

For me, the issue was being inside a conda environment. Most likely it used the pip command from the conda environment ("where pip" pointed to the conda environment). Setting proxy-settings via --proxy or set http_proxy did not help.

Instead, simply opening a new CMD and doing "pip install " there, helped.

What is the difference between int, Int16, Int32 and Int64?

Nothing. The sole difference between the types is their size (and, hence, the range of values they can represent).

JQuery - Call the jquery button click event based on name property

$('element[name="element_name"]').click(function(){
    //do stuff
});

in your case:

$('input[name="btnName"]').click(function(){
    //do stuff
});

Can a table have two foreign keys?

Yes, MySQL allows this. You can have multiple foreign keys on the same table.

Get more details here FOREIGN KEY Constraints

How to send only one UDP packet with netcat?

I had the same problem but I use -w 0 option to send only one packet and quit. You should use this command :

echo -n "hello" | nc -4u -w0 localhost 8000

How to break out of nested loops?

You'll need a boolean variable, if you want it readable:

bool broke = false;
for(int i = 0; i < 1000; i++) {
  for(int j = 0; j < 1000; i++) {
    if (condition) {
      broke = true;
      break;
    }
  }
  if (broke)
    break;
}

If you want it less readable you can join the boolean evaluation:

bool broke = false;
for(int i = 0; i < 1000 && !broke; i++) {
  for(int j = 0; j < 1000; i++) {
    if (condition) {
      broke = true;
      break;
    }
  }
}

As an ultimate way you can invalidate the initial loop:

for(int i = 0; i < size; i++) {
  for(int j = 0; j < 1000; i++) {
    if (condition) {
      i = size;
      break;
    }
  }
}

How to use phpexcel to read data and insert into database?

      if($query)
       {
        // try to export to excel the whole data ---
        //initialize php excel first  
        ob_end_clean();
        //--- create php excel object ---
        $objPHPExcel = new PHPExcel();
        //define cachemethod
        ini_set('memory_limit', '3500M');
        $cacheMethod   = PHPExcel_CachedObjectStorageFactory::cache_to_phpTemp;
        $cacheSettings = array('memoryCacheSize' => '800MB');
        //set php excel settings
        PHPExcel_Settings::setCacheStorageMethod(
                $cacheMethod,$cacheSettings
              );


        $objPHPExcel->getProperties()->setTitle("export")->setDescription("none");

        $objPHPExcel->setActiveSheetIndex(0);

        // Field names in the first row
        $fields = $query->list_fields();
        $col = 0;
        foreach ($fields as $field)
        {
            $objPHPExcel->getActiveSheet()->setCellValueByColumnAndRow($col, 1, $field);
            $col++;
        }

        // Fetching the table data
        $row = 2;
        foreach($query->result() as $data)
        {
            $col = 0;
            foreach ($fields as $field)
            {
                $objPHPExcel->getActiveSheet()->setCellValueByColumnAndRow($col, $row, $data->$field);
                $col++;
            }

            $row++;
        }

        $objPHPExcel->setActiveSheetIndex(0);
        //redirect to cleint browser
        header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
        header('Content-Disposition: attachment;filename=Provinces.xlsx');
        header('Cache-Control: max-age=0');

        $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
        $objWriter->save('php://output');
     }

MacOSX homebrew mysql root password

Terminal 1:

$ mysql_safe

Terminal 2:

$ mysql -u root
mysql> UPDATE mysql.user SET Password=PASSWORD('new-password') WHERE User='root';
mysql> FLUSH PRIVILEGES;
mysql> quit

C++: How to round a double to an int?

It is worth noting that what you're doing isn't rounding, it's casting. Casting using (int) x truncates the decimal value of x. As in your example, if x = 3.9995, the .9995 gets truncated and x = 3.

As proposed by many others, one solution is to add 0.5 to x, and then cast.

No connection could be made because the target machine actively refused it 127.0.0.1:3446

I had a similar issue. In my case the service would work fine on the developer machine but fail when on a QA machine. It turned out that on the QA machine the application wasn't being run as an administrator and didn't have permission to register the endpoint:

HTTP could not register URL http://+:12345/Foo.svc/]. Your process does not have access rights to this namespace (see http://go.microsoft.com/fwlink/?LinkId=70353 for details).

Refer here for how to get it working without being an admin user: https://stackoverflow.com/a/885765/38258

How to implement 2D vector array?

vector<vector> matrix(row, vector(col, 0));

This will initialize a 2D vector of rows=row and columns = col with all initial values as 0. No need to initialize and use resize.

Since the vector is initialized with size, you can use "[]" operator as in array to modify the vector.

matrix[x][y] = 2;

sudo: port: command not found

What do you get from running which port as your regular user account? Try it from a freshly opened terminal. Try again after renaming .bash_profile to .profile. Can you run port as a regular user, even with no arguments?

Cache busting via params

It is safer to put the version number in the actual filename. This allows multiple versions to exist at once so you can roll out a new version and if any cached HTML pages still exist that are requesting the older version, they will get the version that works with their HTML.

Note, in one of the largest versioned deployments anywhere on the internet, jQuery uses version numbers in the actual filename and it safely allows multiple versions to co-exist without any special server-side logic (each version is just a different file).

This busts the cache once when you deploy new pages and new linked files (which is what you want) and from then on those versions can be effectively cached (which you also want).

SSRS chart does not show all labels on Horizontal axis

Go to Horizontal axis properties,choose 'Category' in AXIS type,choose "Disabled" in SIDE Margin option

How can I insert values into a table, using a subquery with more than one result?

the sub query looks like

 insert into table_name (col1,col2,....) values (select col1,col2,... FROM table_2 ...)

hope this help

How to set maximum fullscreen in vmware?

Change the resolution of your operating system running in VMware and hope it will stretch the screen when chosen the correct values

Why is &#65279; appearing in my HTML?

Just use notepad ++ with encoding UTF-8 without BOM.

How do I request a file but not save it with Wget?

Curl does that by default without any parameters or flags, I would use it for your purposes:

curl $url > /dev/null 2>&1

Curl is more about streams and wget is more about copying sites based on this comparison.

How to listen for changes to a MongoDB collection?

MongoDB version 3.6 now includes change streams which is essentially an API on top of the OpLog allowing for trigger/notification-like use cases.

Here is a link to a Java example: http://mongodb.github.io/mongo-java-driver/3.6/driver/tutorials/change-streams/

A NodeJS example might look something like:

 var MongoClient = require('mongodb').MongoClient;
    MongoClient.connect("mongodb://localhost:22000/MyStore?readConcern=majority")
     .then(function(client){
       let db = client.db('MyStore')

       let change_streams = db.collection('products').watch()
          change_streams.on('change', function(change){
            console.log(JSON.stringify(change));
          });
      });

VBA EXCEL Multiple Nested FOR Loops that Set two variable for expression

I can't get to your google docs file at the moment but there are some issues with your code that I will try to address while answering

Sub stituterangersNEW()
Dim t As Range
Dim x As Range
Dim dify As Boolean
Dim difx As Boolean
Dim time2 As Date
Dim time1 As Date

    'You said time1 doesn't change, so I left it in a singe cell.
    'If that is not correct, you will have to play with this some more.
    time1 = Range("A6").Value

    'Looping through each of our output cells.
    For Each t In Range("B7:E9") 'Change these to match your real ranges.

        'Looping through each departure date/time.
        '(Only one row in your example. This can be adjusted if needed.)
        For Each x In Range("B2:E2") 'Change these to match your real ranges.
            'Check to see if our dep time corresponds to
            'the matching column in our output
            If t.Column = x.Column Then
                'If it does, then check to see what our time value is
                If x > 0 Then
                    time2 = x.Value
                    'Apply the change to the output cell.
                    t.Value = time1 - time2
                    'Exit out of this loop and move to the next output cell.
                    Exit For
                End If
            End If
            'If the columns don't match, or the x value is not a time
            'then we'll move to the next dep time (x)
        Next x
    Next t

End Sub

EDIT

I changed you worksheet to play with (see above for the new Sub). This probably does not suite your needs directly, but hopefully it will demonstrate the conept behind what I think you want to do. Please keep in mind that this code does not follow all the coding best preactices I would recommend (e.g. validating the time is actually a TIME and not some random other data type).

     A                      B                   C                   D                  E
1    LOAD_NUMBER            1                   2                   3                  4
2    DEPARTURE_TIME_DATE    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 20:00                
4    Dry_Refrig 7585.1  0   10099.8 16700
6    1/4/2012 19:30

Using the sub I got this output:

    A           B             C             D             E
7   Friday      1272:00:00    1272:00:00    1272:00:00    1271:30:00
8   Saturday    1272:00:00    1272:00:00    1272:00:00    1271:30:00
9   Thursday    1272:00:00    1272:00:00    1272:00:00    1271:30:00

How do I access (read, write) Google Sheets spreadsheets with Python?

(Jun-Dec 2016) Most answers here are now out-of-date as: 1) GData APIs are the previous generation of Google APIs, and that's why it was hard for @Josh Brown to find that old GData Docs API documentation. While not all GData APIs have been deprecated, all newer Google APIs do not use the Google Data protocol; and 2) Google released a new Google Sheets API (not GData). In order to use the new API, you need to get the Google APIs Client Library for Python (it's as easy as pip install -U google-api-python-client [or pip3 for Python 3]) and use the latest Sheets API v4+, which is much more powerful & flexible than older API releases.

Here's one code sample from the official docs to help get you kickstarted. However, here are slightly longer, more "real-world" examples of using the API you can learn from (videos plus blog posts):

The latest Sheets API provides features not available in older releases, namely giving developers programmatic access to a Sheet as if you were using the user interface (create frozen rows, perform cell formatting, resizing rows/columns, adding pivot tables, creating charts, etc.), but NOT as if it was some database that you could perform searches on and get selected rows from. You'd basically have to build a querying layer on top of the API that does this. One alternative is to use the Google Charts Visualization API query language, which does support SQL-like querying. You can also query from within the Sheet itself. Be aware that this functionality existed before the v4 API, and that the security model was updated in Aug 2016. To learn more, check my G+ reshare to a full write-up from a Google Developer Expert.

Also note that the Sheets API is primarily for programmatically accessing spreadsheet operations & functionality as described above, but to perform file-level access such as imports/exports, copy, move, rename, etc., use the Google Drive API instead. Examples of using the Drive API:

(*) - TL;DR: upload plain text file to Drive, import/convert to Google Docs format, then export that Doc as PDF. Post above uses Drive API v2; this follow-up post describes migrating it to Drive API v3, and here's a developer video combining both "poor man's converter" posts.

To learn more about how to use Google APIs with Python in general, check out my blog as well as a variety of Google developer videos (series 1 and series 2) I'm producing.

ps. As far as Google Docs goes, there isn't a REST API available at this time, so the only way to programmatically access a Doc is by using Google Apps Script (which like Node.js is JavaScript outside of the browser, but instead of running on a Node server, these apps run in Google's cloud; also check out my intro video.) With Apps Script, you can build a Docs app or an add-on for Docs (and other things like Sheets & Forms).

UPDATE Jul 2018: The above "ps." is no longer true. The G Suite developer team pre-announced a new Google Docs REST API at Google Cloud NEXT '18. Developers interested in getting into the early access program for the new API should register at https://developers.google.com/docs.

UPDATE Feb 2019: The Docs API launched to preview last July is now available generally to all... read the launch post for more details.

UPDATE Nov 2019: In an effort to bring G Suite and GCP APIs more inline with each other, earlier this year, all G Suite code samples were partially integrated with GCP's newer (lower-level not product) Python client libraries. The way auth is done is similar but (currently) requires a tiny bit more code to manage token storage, meaning rather than our libraries manage storage.json, you'll store them using pickle (token.pickle or whatever name you prefer) instead, or choose your own form of persistent storage. For you readers here, take a look at the updated Python quickstart example.

Can't execute jar- file: "no main manifest attribute"

I tried this and it worked for me. mvn clean install package should work.

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <executions>
            <execution>
                <goals>
                    <goal>repackage</goal>
                </goals>
            </execution>
            </executions>
        </plugin>
    </plugins>
</build>

issue ORA-00001: unique constraint violated coming in INSERT/UPDATE

Oracle's error message should be somewhat longer. It usually looks like this:

ORA-00001: unique constraint (TABLE_UK1) violated

The name in parentheses is the constrait name. It tells you which constraint was violated.

How to display JavaScript variables in a HTML page without document.write

Similar to above, but I used (this was in CSHTML):

JavaScript:

var value = "Hello World!"<br>
$('.output').html(value);

CSHTML:

<div class="output"></div>

Installing R on Mac - Warning messages: Setting LC_CTYPE failed, using "C"

Just open the R(software) and copy and paste

system("defaults write org.R-project.R force.LANG en_US.UTF-8")

Hope this will work fine or use the other method

open(on mac): Utilities/Terminal copy and paste

defaults write org.R-project.R force.LANG en_US.UTF-8

and close both terminal and R and reopen R.

How to prevent colliders from passing through each other?

I have a pinball prototype that also gave me much trouble in the same areas. These are all the steps I've taken to almost (but not yet entirely) solve these problems:

For fast moving objects:

  • Set the rigidbody's Interpolate to 'Interpolate' (this does not affect the actual physics simulation, but updates the rendering of the object properly - use this only on important objects from a rendering point of view, like the player, or a pinball, but not for projectiles)

  • Set Collision Detection to Continuous Dynamic

  • Attach the script DontGoThroughThings (https://www.auto.tuwien.ac.at/wordpress/?p=260) to your object. This script cleverly uses the Raycasting solution I posted in my other answer to pull back offending objects to before the collision points.

In Edit -> Project Settings -> Physics:

  • Set Min Penetration for Penalty to a very low value. I've set mine to 0.001

  • Set Solver Iteration Count to a higher value. I've set mine to 50, but you can probably do ok with much less.

All that is going to have a penalty in performace, but that's unavoidable. The defaults values are soft on performance but are not really intented for proper simulation of small and fast-moving objects.

Difference between shared objects (.so), static libraries (.a), and DLL's (.so)?

You are correct in that static files are copied to the application at link-time, and that shared files are just verified at link time and loaded at runtime.

The dlopen call is not only for shared objects, if the application wishes to do so at runtime on its behalf, otherwise the shared objects are loaded automatically when the application starts. DLLS and .so are the same thing. the dlopen exists to add even more fine-grained dynamic loading abilities for processes. You dont have to use dlopen yourself to open/use the DLLs, that happens too at application startup.

Align labels in form next to input

I use something similar to this:

<div class="form-element">
  <label for="foo">Long Label</label>
  <input type="text" name="foo" id="foo" />
</div>

Style:

.form-element label {
    display: inline-block;
    width: 150px;
}

Reloading a ViewController

You really don't need to do:

[self.view setNeedsDisplay];

Honestly, I think it's "let's hope for the best" type of solution, in this case. There are several approaches to update your UIViews:

  1. KVO
  2. Notifications
  3. Delegation

Each one has is pros and cons. Depending of what you are updating and what kind of "connection" you have between your business layer (the server connectivity) and the UIViewController, I can recommend one that would suit your needs.

Prevent textbox autofill with previously entered values

By making AutoCompleteType="Disabled",

    <asp:TextBox runat="server" ID="txt_userid" AutoCompleteType="Disabled"></asp:TextBox>  

By setting autocomplete="off",

    <asp:TextBox runat="server" ID="txt_userid" autocomplete="off"></asp:TextBox>  

By Setting Form autocomplete="off",

    <form id="form1" runat="server" autocomplete="off">  
    //your content  
    </form>  

By using code in .cs page,

    protected void Page_Load(object sender, EventArgs e)   
    {  
        if (!Page.IsPostBack)  
        {  
            txt_userid.Attributes.Add("autocomplete", "off");  
        }  
    }  

By Using Jquery

    <head runat = "server" >  
        < title > < /title> < script src = "Scripts/jquery-1.6.4.min.js" > < /script> < script type = "text/javascript" >  
        $(document).ready(function()  
        {  
            $('#txt_userid').attr('autocomplete', 'off');  
        });  
    //document.getElementById("txt_userid").autocomplete = "off"  
    < /script>  

and here is my textbox in ,

    <asp:TextBox runat="server" ID="txt_userid" ></asp:TextBox>  

By Setting textbox attribute in code,

    protected void Page_Load(object sender, EventArgs e)   
    {  
        if (!Page.IsPostBack)  
        {  
            txt_userid.Attributes.Add("autocomplete", "off");  
        }  
    } 

Math operations from string

Regex won't help much. First of all, you will want to take into account the operators precedence, and second, you need to work with parentheses which is impossible with regex.

Depending on what exactly kind of expression you need to parse, you may try either Python AST or (more likely) pyparsing. But, first of all, I'd recommend to read something about syntax analysis in general and the Shunting yard algorithm in particular.

And fight the temptation of using eval, that's not safe.

Add padding on view programmatically

use below method for setting padding dynamically

setPadding(int left, int top, int right, int bottom)

Example :

view.setPadding(2,2,2,2);

Ubuntu - Run command on start-up with "sudo"

You can add the command in the /etc/rc.local script that is executed at the end of startup.

Write the command before exit 0. Anything written after exit 0 will never be executed.

Make the current commit the only (initial) commit in a Git repository?

I solved a similar issue by just deleting the .git folder from my project and reintegrating with version control through IntelliJ. Note: The .git folder is hidden. You can view it in the terminal with ls -a , and then remove it using rm -rf .git .

XPath to select element based on childs child value

Almost there. In your predicate, you want a relative path, so change

./book[/author/name = 'John'] 

to either

./book[author/name = 'John'] 

or

./book[./author/name = 'John'] 

and you will match your element. Your current predicate goes back to the root of the document to look for an author.

how to use #ifdef with an OR condition?

Like this

#if defined(LINUX) || defined(ANDROID)

How do I connect to this localhost from another computer on the same network?

If you are on Windows, use ipconfig to get the local IPv4 address, and then specify that under your Apache configuration file: httpd.conf, like:

Listen: 10.20.30.40:80

Restart your Apache server and test it from other computer on the network.

How does data binding work in AngularJS?

Here is an example of data binding with AngularJS, using an input field. I will explain later

HTML Code

<div ng-app="myApp" ng-controller="myCtrl" class="formInput">
     <input type="text" ng-model="watchInput" Placeholder="type something"/>
     <p>{{watchInput}}</p> 
</div>

AngularJS Code

myApp = angular.module ("myApp", []);
myApp.controller("myCtrl", ["$scope", function($scope){
  //Your Controller code goes here
}]);

As you can see in the example above, AngularJS uses ng-model to listen and watch what happens on HTML elements, especially on input fields. When something happens, do something. In our case, ng-model is bind to our view, using the mustache notation {{}}. Whatever is typed inside the input field is displayed on the screen instantly. And that's the beauty of data binding, using AngularJS in its simplest form.

Hope this helps.

See a working example here on Codepen

support FragmentPagerAdapter holds reference to old fragments

I solved the problem by saving the fragments in SparceArray:

public abstract class SaveFragmentsPagerAdapter extends FragmentPagerAdapter {

    SparseArray<Fragment> fragments = new SparseArray<>();

    public SaveFragmentsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        Fragment fragment = (Fragment) super.instantiateItem(container, position);
        fragments.append(position, fragment);
        return fragment;
    }

    @Nullable
    public Fragment getFragmentByPosition(int position){
        return fragments.get(position);
    }

}

How to print the array?

What you are doing is printing the value in the array at spot [3][3], which is invalid for a 3by3 array, you need to loop over all the spots and print them.

for(int i = 0; i < 3; i++) {
    for(int j = 0; j < 3; j++) {
        printf("%d ", array[i][j]);
    }
    printf("\n");
} 

This will print it in the following format

10 23 42
1 654 0
40652 22 0

if you want more exact formatting you'll have to change how the printf is formatted.

bash script use cut command at variable and store result at another variable

The awk solution is what I would use, but if you want to understand your problems with bash, here is a revised version of your script.

#!/bin/bash -vx

##config file with ip addresses like 10.10.10.1:80
file=config.txt

while read line ; do
  ##this line is not correct, should strip :port and store to ip var
  ip=$( echo "$line" |cut -d\: -f1 )
  ping $ip
done < ${file}

You could write your top line as

for line in $(cat $file) ; do ...

(but not recommended).

You needed command substitution $( ... ) to get the value assigned to $ip

reading lines from a file is usually considered more efficient with the while read line ... done < ${file} pattern.

I hope this helps.

Is there a "standard" format for command line/shell help text?

I think there is no standard syntax for command line usage, but most use this convention:

Microsoft Command-Line Syntax, IBM has similar Command-Line Syntax


  • Text without brackets or braces

    Items you must type as shown

  • <Text inside angle brackets>

    Placeholder for which you must supply a value

  • [Text inside square brackets]

    Optional items

  • {Text inside braces}

    Set of required items; choose one

  • Vertical bar {a|b}

    Separator for mutually exclusive items; choose one

  • Ellipsis <file> …

    Items that can be repeated

Calling a Sub and returning a value

Sub don't return values and functions don't have side effects.

Sometimes you want both side effect and return value.

This is easy to be done once you know that VBA passes arguments by default by reference so you can write your code in this way:

Sub getValue(retValue as Long)
    ...
    retValue = 42 
End SUb 

Sub Main()
    Dim retValue As Long
    getValue retValue 
    ... 
End SUb

How to get the Parent's parent directory in Powershell?

You can use

(get-item $scriptPath).Directoryname

to get the string path or if you want the Directory type use:

(get-item $scriptPath).Directory

python date of the previous month

For someone who got here and looking to get both the first and last day of the previous month:

from datetime import date, timedelta

last_day_of_prev_month = date.today().replace(day=1) - timedelta(days=1)

start_day_of_prev_month = date.today().replace(day=1) - timedelta(days=last_day_of_prev_month.day)

# For printing results
print("First day of prev month:", start_day_of_prev_month)
print("Last day of prev month:", last_day_of_prev_month)

Output:

First day of prev month: 2019-02-01
Last day of prev month: 2019-02-28

presentViewController and displaying navigation bar

If you didn't set the modalPresentationStyle property (like to UIModalPresentationFormSheet), the navigation bar will be displayed always. To ensure, always do

[[self.navigationController topViewController] presentViewController:vieController 
                                                            animated:YES 
                                                          completion:nil];

This will show the navigation bar always.

How can one create an overlay in css?

I was just playing around with a similar problem on codepen, this is what I did to create an overlay using a simple css markup. I created a div element with class .box applied to it. Inside this div I created two divs, one with .inner class applied to it and the other with .notext class applied to it. Both of these classes inside the .box div are initially set to display:none but when the .box is hovered over, these are made visible.

_x000D_
_x000D_
.box{_x000D_
  height:450px;_x000D_
  width:450px;_x000D_
  border:1px solid black;_x000D_
  margin-top:50px;_x000D_
  display:inline-block;_x000D_
  margin-left:50px;_x000D_
  transition: width 2s, height 2s;_x000D_
  position:relative;_x000D_
  text-align: center;_x000D_
    background:url('https://upload.wikimedia.org/wikipedia/commons/c/cd/Panda_Cub_from_Wolong,_Sichuan,_China.JPG');_x000D_
  background-size:cover;_x000D_
  background-position:center;_x000D_
  _x000D_
}_x000D_
.box:hover{_x000D_
  width:490px;_x000D_
  height:490px;_x000D_
}_x000D_
.inner{_x000D_
  border:1px solid red;_x000D_
  position:relative;_x000D_
  width:100%;_x000D_
  height:100%;_x000D_
  top:0px;_x000D_
  left:0px;_x000D_
  display:none; _x000D_
  color:white;_x000D_
  font-size:xx-large;_x000D_
  z-index:10;_x000D_
}_x000D_
.box:hover > .inner{_x000D_
  display:inline-block;_x000D_
}_x000D_
.notext{_x000D_
  height:30px;_x000D_
  width:30px;_x000D_
  border:1px solid blue;_x000D_
  position:absolute;_x000D_
  top:0px;_x000D_
  left:0px;_x000D_
  width:100%;_x000D_
  height:100%;_x000D_
  display:none;_x000D_
}_x000D_
.box:hover > .notext{_x000D_
  background-color:black;_x000D_
  opacity:0.5;_x000D_
  display:inline-block;_x000D_
}
_x000D_
<div class="box">_x000D_
  <div class="inner">_x000D_
    <p>Panda!</p>_x000D_
  </div>_x000D_
  <div class="notext"></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Hope this helps! :) Any suggestions are welcome.

Reversing a String with Recursion in Java

AFAIK, there 2 thing in every recursion function :

  1. There is always a stop condition which is :

    if ((null == str) || (str.length() <= 1)) { return str; }

  2. Recursion use the stack memory which use LIFO mechanism that's why the revert happen.

undefined reference to boost::system::system_category() when compiling

When using CMAKE and find_package, make sure it is :

find_package(Boost COMPONENTS system ...)

and not

find_package(boost COMPONENTS system ...)

Some people may have lost hours for that ...

Aggregate / summarize multiple variables per group (e.g. sum, mean)

Where is this year() function from?

You could also use the reshape2 package for this task:

require(reshape2)
df_melt <- melt(df1, id = c("date", "year", "month"))
dcast(df_melt, year + month ~ variable, sum)
#  year month         x1           x2
1  2000     1  -80.83405 -224.9540159
2  2000     2 -223.76331 -288.2418017
3  2000     3 -188.83930 -481.5601913
4  2000     4 -197.47797 -473.7137420
5  2000     5 -259.07928 -372.4563522

What is the difference between Cloud, Grid and Cluster?

Cluster differs from Cloud and Grid in that a cluster is a group of computers connected by a local area network (LAN), whereas cloud and grid are more wide scale and can be geographically distributed. Another way to put it is to say that a cluster is tightly coupled, whereas a Grid or a cloud is loosely coupled. Also, clusters are made up of machines with similar hardware, whereas clouds and grids are made up of machines with possibly very different hardware configurations.

To know more about cloud computing, I recommend reading this paper: «Above the Clouds: A Berkeley View of Cloud Computing», Michael Armbrust, Armando Fox, Rean Griffith, Anthony D. Joseph, Randy H. Katz, Andrew Konwinski, Gunho Lee, David A. Patterson, Ariel Rabkin, Ion Stoica and Matei Zaharia. The following is an abstract from the above paper:

Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services. The services themselves have long been referred to as Software as a Service (SaaS). The datacenter hardware and software is what we call a Cloud. When a Cloud is made available in a pay-as-you-go manner to the general public, we call it a Public Cloud; the service being sold is Utility Computing. We use the term Private Cloud to refer to internal datacenters of a business or other organization, not made available to the general public. Thus, Cloud Computing is the sum of SaaS and Utility Computing, but does not include Private Clouds. People can be users or providers of SaaS, or users or providers of Utility Computing.

The difference between a cloud and a grid can be expressed as below:

  1. Resource distribution: Cloud computing is a centralized model whereas grid computing is a decentralized model where the computation could occur over many administrative domains.

  2. Ownership: A grid is a collection of computers which is owned by multiple parties in multiple locations and connected together so that users can share the combined power of resources. Whereas a cloud is a collection of computers usually owned by a single party.

Examples of Clouds: Amazon Web Services (AWS), Google App Engine.

Examples of Grids: FutureGrid.

Examples of cloud computing services: Dropbox, Gmail, Facebook, Youtube, RapidShare.

Storing image in database directly or as base64 data?

I recommend looking at modern databases like NoSQL and also I agree with user1252434's post. For instance I am storing a few < 500kb PNGs as base64 on my Mongo db with binary set to true with no performance hit at all. Mongo can be used to store large files like 10MB videos and that can offer huge time saving advantages in metadata searches for those videos, see storing large objects and files in mongodb.

How do you install and run Mocha, the Node.js testing module? Getting "mocha: command not found" after install

To run Mocha with mocha command from your terminal you need to install mocha globally on this machine:

npm install --global mocha

Then cd to your projectFolder/test and run mocha yourTestFileName.js


If you want to make mocha available inside your package.json as a development dependency:

npm install --save-dev mocha

Then add mocha to your scripts inside package.json.

"scripts": {
    "test": "mocha"
  },

Then run npm test inside your terminal.

How do I center an anchor element in CSS?

write like this:

<div class="parent">
 <a href="http://www.example.com">example</a>
</div>

CSS

.parent{
  text-align:center
}

jQuery: How to detect window width on the fly?

Changing a variable doesn't magically execute code within the if-block. Place the common code in a function, then bind the event, and call the function:

$(document).ready(function() {
    // Optimalisation: Store the references outside the event handler:
    var $window = $(window);
    var $pane = $('#pane1');

    function checkWidth() {
        var windowsize = $window.width();
        if (windowsize > 440) {
            //if the window is greater than 440px wide then turn on jScrollPane..
            $pane.jScrollPane({
               scrollbarWidth:15, 
               scrollbarMargin:52
            });
        }
    }
    // Execute on load
    checkWidth();
    // Bind event listener
    $(window).resize(checkWidth);
});

How to perform Join between multiple tables in LINQ lambda

take look at this sample code from my project

public static IList<Letter> GetDepartmentLettersLinq(int departmentId)
{
    IEnumerable<Letter> allDepartmentLetters =
        from allLetter in LetterService.GetAllLetters()
        join allUser in UserService.GetAllUsers() on allLetter.EmployeeID equals allUser.ID into usersGroup
        from user in usersGroup.DefaultIfEmpty()// here is the tricky part
        join allDepartment in DepartmentService.GetAllDepartments() on user.DepartmentID equals allDepartment.ID
        where allDepartment.ID == departmentId
        select allLetter;

    return allDepartmentLetters.ToArray();
}

in this code I joined 3 tables and I spited join condition from where clause

note: the Services classes are just warped(encapsulate) the database operations

What is the best way to get the count/length/size of an iterator?

Your code will give you an exception when you reach the end of the iterator. You could do:

int i = 0;
while(iterator.hasNext()) {
    i++;
    iterator.next();
}

If you had access to the underlying collection, you would be able to call coll.size()...

EDIT OK you have amended...

ASP.NET Web Application Message Box

Right click the solution explorer and choose the add reference.one dialog box will be appear. On that select (.net)-> System.windows.form. Imports System.Windows.Forms (vb) and using System.windows.forms(C#) copy this in your coding and then write messagebox.show("").

Generate random password string with requirements in javascript

Easily generate random passwords with the help of this JavaScript code. For demo click: How to generate random passwords using JavaScript

JavaScript code:

<script>
const input = document.querySelector("input");
const button = document.querySelector("#passgen");
function GeneratePassword(length = 8) {
const cwb =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789@#$!%^&*()_+=-";

  let password = "";
  for (let i = 0; i < length; ++i) {
    let at = Math.floor(Math.random() * (cwb.length + 1));
    password += cwb.charAt(at);
  }
  return password;
}
button.addEventListener("click", () => {
  input.value = GeneratePassword(8);
});
</script> 

How to install APK from PC?

Airdroid , android market install the app on android then go onto the computer type in the address given, type in the password given (or scan the QR code). Go to settings and under security (if your running the new ICS or Jellybean) or go to settings->apps->managment and select unknown sources(for gingerbread) then click on (I think) speed install, or something along those lines. it will be on the top of the page slightly towards the left. drag and drop as many .apks as you want then on you android just tap the install buttons that appear. Airdroid is wonderful and does a lot more than just apks.

Checking password match while typing

if we use bootstrap our text will be green or red depending on the result

HTML

<div class="col-12 col-md-6 col-lg-4 mb-3">
            <label class="form-group d-block mb-0">
        <span class="text-secondary d-block font-weight-semibold mb-1">New Password</span>
<input type="password" id="txtNewPassword" class="form-control">     
        </label>
        </div>
        <div class="col-12 col-md-6 col-lg-4 mb-3">
            <label class="form-group d-block mb-0">
        <span class="text-secondary d-block font-weight-semibold mb-1">Confirm Password
        </span>
        <input class="form-control" type="password" id="txtConfirmPassword" onkeyup="checkPasswordMatch();">   
            </label>
        </div>
        <div class="registrationFormAlert" id="divCheckPasswordMatch"></div>

CSS

.text-success {
    color: #28a745;
}
.text-danger {
    color: #dc3545;
}

JS

function checkPasswordMatch() {
        var password = $("#txtNewPassword").val();
        var confirmPassword = $("#txtConfirmPassword").val();

        if (password != confirmPassword)
            $("#divCheckPasswordMatch").html("Passwords do not match!").addClass('text-danger').removeClass('text-success');

        else
            $("#divCheckPasswordMatch").html("Passwords match.").addClass('text-success').removeClass('text-danger');
    }

Pure JavaScript: a function like jQuery's isNumeric()

There's no isNumeric() type of function, but you could add your own:

function isNumeric(n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
}

NOTE: Since parseInt() is not a proper way to check for numeric it should NOT be used.

How to get the cell value by column name not by index in GridView in asp.net

Although its a long time but this relatively small piece of code seems easy to read and get:

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
   int index;
   string cellContent;

    foreach (TableCell tc in ((GridView)sender).HeaderRow.Cells)
    {
       if( tc.Text.Equals("yourColumnName") )
       {
         index = ((GridView)sender).HeaderRow.Cells.GetCellIndex(tc);
         cellContent = ((GridView)sender).SelectedRow.Cells[index].Text;
         break;
       }
    }
}