That would be a two-dimensional array. You can also specify more dimensions:

[Multidimensional Arrays (C# Programming Guide)][1]


  [1]: http://msdn.microsoft.com/en-us/library/2yd9wwz4.aspx

Each comma adds an additional dimension to the array [,] = 2 dimensional [,,] = 3 dimensional ...


That the array is multi-dimensional - two-dimensional in your case.

It means it is a multidimensional array.

See [MSDN][1].


  [1]: http://msdn.microsoft.com/en-us/library/aa288453%28v=vs.71%29.aspx

&gt; **Possible Duplicate:**  
&gt; [How does prototype extend on typescript?](https://stackoverflow.com/questions/12766117/how-does-prototype-extend-on-typescript)  

&lt;!-- End of automatically inserted text --&gt;

I am currently learning TypeScript, and would like to know how it is possible to add functionality to existing objects. Say I want to add an implementation for Foo to the String object. In JavaScript I would do this:

    String.prototype.Foo = function() {
    	// DO THIS...
    }

Understanding that TypeScript classes, interfaces and modules are open ended led me to try the following, without success

*1. Reference the JavaScript implementation from TypeScript*

        JavaScript:
    
    	String.prototype.Foo = function() {
    		// DO THIS...
    	}
    
    	TypeScript:
    
    	var x = &quot;Hello World&quot;;
    	x.Foo(); //ERROR, Method does not exist


*2. Extend the interface*

	interface String {
		Foo(): number;
	}

	var x = &quot;Hello World&quot;;
	x.Foo(); //Exists but no implementation.

*3. Extend the class*

	class String {
		Foo(): number {
			return 0;
		}
	}

	// ERROR: Duplicate identifier &#39;String&#39;

As you can see from these results, so far I have been able to add the method via an interface contract, but no implementation, so, how do I go about defining AND implementing my Foo method as part of the pre-existing String class?


Extending functionality in TypeScript

I am having some seemingly trivial trouble with numpy when the array contains string data.  I have the following code:    

    my_array = numpy.empty([1, 2], dtype = str)
    my_array[0, 0] = &quot;Cat&quot;
    my_array[0, 1] = &quot;Apple&quot;

Now, when I print it with `print my_array[0, :]`, the response I get is `[&#39;C&#39;, &#39;A&#39;]`, which is clearly not the expected output of Cat and Apple.  Why is that, and how can I get the right output?

Thanks!

Weird behaviour initializing a numpy array of string data

I have some code I&#39;m trying to understand while learning C#.  I do not understand what I even need to search Google for to get here, but the code is as follows:

    float[,] heightAll = terData.GetHeights(0, 0, allWidth, allHeight);

Why does the array declaration have a comma in between the brackets?

What does it mean when there is a comma inside an array declaration? e.g. float[,]

I have some code I'm trying to understand while learning C#. I do not understand what I even need to search Google for to get here, but the code is as follows:
<pre><code class="hljs language-ini">float[,] heightAll = terData.GetHeights(0, 0, allWidth, allHeight);
</code></pre>
Why does the array declaration have a comma in between the brackets?

Here is a **DataTable dt**, which has lots of data. 

I want to get the specific **Cell Value** from the DataTable, say **Cell[i,j]**. Where, 
i -&gt; Rows and j -&gt; Columns. I will iterate i,j&#39;s value with two `forloops`.

But I can&#39;t figure out how I can call a cell by its index.

Here&#39;s the code: 

    for (i = 0; i &lt;= dt.Rows.Count - 1; i++)
    {
        for (j = 0; j &lt;= dt.Columns.Count - 1; j++)
        {
            var cell = dt.Rows[i][j];
            xlWorkSheet.Cells[i + 1, j + 1] = cell;
        }
    }

Get Cell Value from a DataTable in C#

TL;DR - I&#39;m looking for xUnit&#39;s equivalent of MSTest&#39;s `AssemblyInitialize` (aka the ONE feature it has that I like).

Specifically I&#39;m looking for it because I have some Selenium smoke tests which I would like to be able to run with no other dependencies.  I have a Fixture that will launch IisExpress for me and kill it on disposal. But doing this before every test hugely bloats runtime.

I would like to trigger this code once at the start of testing, and dispose of it (shutting down the process) at the end.  How could I go about doing that? 

Even if I can get programmatic access to something like &quot;how many tests are currently being run&quot; I can figure something out.

Run code once before and after ALL tests in xUnit.net

I&#39;m getting this error when trying to parse through an XML document in a C# application:

&gt;&quot;For security reasons DTD is prohibited in this XML document. To enable DTD processing set the ProhibitDtd property on XmlReaderSettings to false and pass the settings into XmlReader.Create method.&quot;

For reference, the exception occurred at the second line of the following code:
    
    using (XmlReader reader = XmlReader.Create(uri))
    {
        reader.MoveToContent(); //here

        while (reader.Read()) //(code to parse xml doc follows).

My knowledge of Xml is pretty limited and I have no idea what DTD processing is nor how to do what the error message suggests. Any help as to what may be causing this and how to fix it? thanks...

DTD prohibited in xml document exception

I am running my application in debug mode, and I would like to manually throw an exception (i.e. not from within the code). Is there any way to do this?

Of course, running `throw new Exception(&quot;My forced exception&quot;);` in the Command or Immediate window doesn&#39;t work.

EDIT: I want the exception to be caught by the try-catch statement that surrounds the code I&#39;m debugging.

How to force an exception while debugging in Visual Studio?

If I run this code:

    Console.WriteLine( String.Format( &quot;{0}&quot;, null ) );

I get a `ArgumentNullException` but if I run this code:

    String str = null;
    Console.WriteLine( String.Format( &quot;{0}&quot;, str ) );

it runs just fine and the output is an empty string.

Now the two piece look equivalent to me - they both pass a null reference into `String.Format()` yet the behavior is different.

How id different behavior possible here?

Why do I get an exception when passing &quot;null&quot; constant but not when passing a &quot;null&quot; string reference?

Let&#39;s say I have an array of four objects:

    var jsObjects = [
       {a: 1, b: 2}, 
       {a: 3, b: 4}, 
       {a: 5, b: 6}, 
       {a: 7, b: 8}
    ];

Is there a way that I can get the third object (`{a: 5, b: 6}`) by the value of the property `b` for example without a `for...in` loop?

Get JavaScript object from array of objects by value of property

I&#39;ve looked around for a few examples here but a lot of them are either too advanced for my grasp of PHP or their examples are too specific to their own projects. I am currently struggling with a very basic part of a PHP form.

I am trying to create a form with a few checkboxes, each assigned a different value, I want these to be sent to a variable (array?) that I can echo/use later, in my case I will be sending the checked values in an email.

So far, I have tried a few variations, but the closest I have come to it is this...

    &lt;form method=&#39;post&#39; id=&#39;userform&#39; action=&#39;thisform.php&#39;&gt;
    &lt;tr&gt;
    	&lt;td&gt;Trouble Type&lt;/td&gt;
    	&lt;td&gt;
    	&lt;input type=&#39;checkbox&#39; name=&#39;checkboxvar&#39; value=&#39;Option One&#39;&gt;1&lt;br&gt;
    	&lt;input type=&#39;checkbox&#39; name=&#39;checkboxvar&#39; value=&#39;Option Two&#39;&gt;2&lt;br&gt;
    	&lt;input type=&#39;checkbox&#39; name=&#39;checkboxvar&#39; value=&#39;Option Three&#39;&gt;3
    	&lt;/td&gt;
    &lt;/tr&gt;
    &lt;/table&gt;
    &lt;input type=&#39;submit&#39; class=&#39;buttons&#39;&gt;
    &lt;/form&gt;
    
    &lt;?php
    $checkboxvar[] = $_REQUEST[&#39;checkboxvar&#39;];
    ?&gt;

Where I&#39;d echo $checkboxvar[] into my email.
Am I going about this completely wrong? The other idea I had was to use a lot of if statements.

PHP Multiple Checkbox Array

I&#39;m using FormData to upload files. I also want to send an array of other data. 

When I send just the image, it works fine. When I append some text to the formdata, it works fine. When I try to attach the &#39;tags&#39; array below, everything else works fine but no array is sent.

Any known issues with FormData and appending arrays?

Instantiate formData:

`formdata = new FormData();`
   
The array I create. Console.log shows everything working fine.

            // Get the tags
    		tags = new Array();
    		$(&#39;.tag-form&#39;).each(function(i){
    			article = $(this).find(&#39;input[name=&quot;article&quot;]&#39;).val();
    			gender = $(this).find(&#39;input[name=&quot;gender&quot;]&#39;).val();
    			brand = $(this).find(&#39;input[name=&quot;brand&quot;]&#39;).val();
    			this_tag = new Array();
    			this_tag.article = article;
    			this_tag.gender = gender;
    			this_tag.brand = brand;
    			tags.push(this_tag);	
    			console.log(&#39;This is tags array: &#39;);
    			console.log(tags);
    		});
    		formdata.append(&#39;tags&#39;, tags);
    		console.log(&#39;This is formdata: &#39;);
    		console.log(formdata);
    
How I send it: 

    		// Send to server
    		$.ajax({
    			url: &quot;../../build/ajaxes/upload-photo.php&quot;,
    			type: &quot;POST&quot;,
    			data: formdata,
    			processData: false,
    			contentType: false,
    			success: function (response) {
    				console.log(response);
    				$.fancybox.close();
    			}
    		});

Can I append an array to &#39;formdata&#39; in javascript?

Suppose the mongodb document(table) &#39;users&#39; is

    {
        _id: 1,
        name: {
            first: &#39;John&#39;,
            last: &#39;Backus&#39;
        },
        birth: new Date(&#39;Dec 03, 1924&#39;),
        death: new Date(&#39;Mar 17, 2007&#39;),
        contribs: [&#39;Fortran&#39;, &#39;ALGOL&#39;, &#39;Backus-Naur Form&#39;, &#39;FP&#39;],
        awards: [
            {
                award: &#39;National Medal&#39;,
                year: 1975,
                by: &#39;NSF&#39;
            },
            {
                award: &#39;Turing Award&#39;,
                year: 1977,
                by: &#39;ACM&#39;
            }
        ]
    }
    // ...and other object(person)s

I want to find the person who has the award &#39;National Medal&#39; and must be awarded in year 1975
There could be other persons who have this award in different years.

How can I find this person using award type and year. So I can get exact person.

How to search in array of object in mongodb

I have an object with several properties. I would like to remove any properties that have falsy values.

This can be achieved with [`compact`](http://underscorejs.org/#compact) on arrays, but what about objects?

Remove empty properties / falsy values from Object with Underscore.js

Has any one seen the array `[]` placed after the method signature like this?

    public static String mySplit(String s)[] {
        return s.split(&quot;,&quot;);
    }

    public static void main(String... args) {
        String[] words = mySplit(&quot;a,b,c,d,e&quot;);
        System.out.println(Arrays.toString(words));
    }

prints

    [a, b, c, d, e]

In the past, odd notations have been for &quot;C&quot; compatibility, but I wouldn&#39;t imagine someone writing this in C either.

Does anyone know why this is even allowed?  

I am using Java 7 update 10, in case it matters.

This does the same thing in Java 6. http://ideone.com/91rZV1


---

BTW this doesn&#39;t compile, nor would I expect it to

    public static &lt;T&gt; List mySplit(String s)&lt;T&gt; {
        return Collections.emptyList();
    }


Strange array return type

In an Eclipse SVN project I have a problem; when I tried to open a declaration of one class, I got this error: 

    Problems opening an editor Reason : projectname does not exist.

Also refactoring does not work.

I have searched the web and tried all found solutions but nothing helped.
I have downloaded different Eclipse and Java versions and switched to a clean workspace but I still have the problem.

How can I solve my problem or which solution can I try?

Eclipse Open declaration in Java project

I came across the data type `int32_t` in a C program recently.  I know that it stores 32 bits, but don&#39;t `int` and `int32` do the same?

Also, I want to use `char` in a program.  Can I use `int8_t` instead? What is the difference?

To summarize: **what is the difference between int32, int, int32_t, int8 and int8_t in C?**

Difference between int32, int, int32_t, int8 and int8_t

I was just going through some code on the Internet and found this:

    float * (*(*foo())[SIZE][SIZE])()

How do I read this declaration? Is there a specific set of rules for reading such complex declarations?


Complex C declaration

When a local (inner) function is declared in JavaScript, there are two options:

Declaring with `var` keyword, assigning to the variable:

    (function() {
        var innerFunction1 = function() { ... };
        innerFunction1();
    }());

Declaring just with the `function` keyword, without assigning to variable:

    (function() {
        function innerFunction2() { ... };
        innerFunction2();
    }());

I can see one advantage of the second: the function can be declared below the code which calls it so it is easier to separate private functions from the code actually executed. 

Which of them is **better** and **why**? 

Content Type	Original Author	Original Content on Stackoverflow
Question	ricky	View Question on Stackoverflow
Solution 1 - C#	Justin Niessner	View Answer on Stackoverflow
Solution 2 - C#	BStateham	View Answer on Stackoverflow
Solution 3 - C#	Igor	View Answer on Stackoverflow
Solution 4 - C#	Ryan	View Answer on Stackoverflow

What does it mean when there is a comma inside an array declaration? e.g. float[,]

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Solution 4 - C#

Weird behaviour initializing a numpy array of string data

Extending functionality in TypeScript

Attributions