You want the GetLength() method of your array:

    a.GetLength(0);

http://msdn.microsoft.com/en-us/library/system.array.getlength.aspx

Use [`Array.Rank`][1] to get number of dimensions and then use [`Array.GetLength(int dimension)`][2] to get the length of a specific dimension. 


  [1]: http://msdn.microsoft.com/en-us/library/system.array.rank.aspx
  [2]: http://msdn.microsoft.com/en-us/library/system.array.getlength.aspx

Use [System.Array.GetLength(int dimension)][1].


  [1]: http://msdn.microsoft.com/en-us/library/system.array.getlength.aspx

I have this snipped in my page:

    $(&#39;#category_sorting_form_save&#39;).click(function(){
        var elements = $(&quot;#category_sorting_elements &gt; div&quot;);
        $.each(elements, function(key, value) {
            console.info(key,&quot; : &quot;,value);
            console.info(&quot;cat_id: &quot;,value.attr(&#39;cat_id&#39;));
        });
    });

And when it is executed, I get:

    0 : &lt;div class=&quot;dragable&quot; cat_id=&quot;6&quot; value=&quot;&quot; style=&quot;opacity: 1;&quot;&gt;    
    value.attr is not a function
        console.info(&quot;cat_id: &quot;,value.attr(&#39;cat_id&#39;));

What am I doing wrong here? I am trying to get the value of the div.cat_id element.


jQuery: value.attr is not a function

We have all heard that one should never rebase published work, that it’s dangerous, etc. However, I have not seen any recipes posted for how to deal with the situation in case a rebase *is* published.

Now, do note that this is only really feasible if the repository is only cloned by a known (and preferably small) group of people, so that whoever pushes the rebase or reset can notify everyone else that they will need to pay attention next time they fetch(!).

One obvious solution that I have seen will work if you have no local commits on `foo` and it gets rebased:

    git fetch
    git checkout foo
    git reset --hard origin/foo

This will simply throw away the local state of `foo` in favour of its history as per the remote repository.

But how does one deal with the situation if one has committed substantial local changes on that branch?

How do I recover/resynchronise after someone pushes a rebase or a reset to a published branch?

If I declare this array...

    string[,] a = {
                      {&quot;0&quot;, &quot;1&quot;, &quot;2&quot;},
                      {&quot;0&quot;, &quot;1&quot;, &quot;2&quot;},
                      {&quot;0&quot;, &quot;1&quot;, &quot;2&quot;},
                      {&quot;0&quot;, &quot;1&quot;, &quot;2&quot;},
                  };

Then I can measure the length with

    a.Length

which is 12. How do I measure the dimension of the arrays within? If I try...

    a[0].Length

I get `Wrong number of indices inside []; expected 2`. What gives?

How do I find the size of a 2D array?

If I declare this array...
<pre><code class="hljs language-c">string[,] a = {
 {"0", "1", "2"},
 {"0", "1", "2"},
 {"0", "1", "2"},
 {"0", "1", "2"},
 };
</code></pre>
Then I can measure the length with
<pre><code class="hljs language-css">a.Length
</code></pre>
which is 12. How do I measure the dimension of the arrays within? If I try...
<pre><code class="hljs language-css">a[0].Length
</code></pre>
I get <code>Wrong number of indices inside []; expected 2</code>. What gives?

I have a collection:

    List&lt;VPair&lt;Item, List&lt;Item&gt;&gt; dependencyHierarchy;

The first item in pair is some object (item) and the second one is a collection of the same type objects that the first one depends on. I want to get a `List&lt;Item&gt;` in order of dependency, so there are not items that depend on the first element and so on (no cycled dependency!).

Input: 

&lt;pre&gt;
Item4 depends on Item3 and Item5
Item3 depends on Item1
Item1 does not depend on any one
Item2 depends on Item4 
Item5 does not depend on any one 
&lt;/pre&gt;

Result:

&lt;pre&gt;
Item1
Item5
Item3
Item4
Item2
&lt;/pre&gt;

Thank you.

**SOLUTION:** 

**Topological Sorting** (thanks to [Lo&#239;c F&#233;vrier][1] for idea) 

and

[example on C#][2], [example on Java][3]  (thanks to [xcud][4] for great examples)


  [1]: https://stackoverflow.com/users/456106/loic-fevrier
  [2]: http://tawani.blogspot.com/2009/02/topological-sorting-and-cyclic.html
  [3]: http://www.java2s.com/Code/Java/Collections-Data-Structure/Topologicalsorting.htm
  [4]: https://stackoverflow.com/users/61396/xcud

How to sort depended objects by dependency

We&#39;ve seen plenty of questions about when and why to use `try`/`catch` and `try`/`catch`/`finally`. And I know there&#39;s definitely a use case for `try`/`finally` (especially since it is the way the `using` statement is implemented).

We&#39;ve also seen questions about &lt;a href=&quot;https://stackoverflow.com/questions/52312/what-is-the-real-overhead-of-try-catch-in-c&quot;&gt;the overhead of try/catch and exceptions&lt;/a&gt;.

The question I linked to, however, doesn&#39;t talk about the overhead of having JUST try-finally.

Assuming there are no exceptions from anything that happens in the `try` block, what&#39;s the overhead of making sure that the `finally` statements get executed on leaving the `try` block (sometimes by returning from the function)?

Again, I&#39;m asking ONLY about `try`/`finally`, no `catch`, no throwing of exceptions.

Thanks!

&lt;b&gt;EDIT:&lt;/b&gt; Okay, I&#39;m going to try to show my use case a little better.

Which should I use, `DoWithTryFinally` or `DoWithoutTryFinally`?

    public bool DoWithTryFinally()
    {
      this.IsBusy = true;
      
      try
      {
        if (DoLongCheckThatWillNotThrowException())
        {
          this.DebugLogSuccess();
          return true;
        }
        else
        {
          this.ErrorLogFailure();
          return false;
        }
      }
      finally
      {
        this.IsBusy = false;
      }
    }
    
    public bool DoWithoutTryFinally()
    {
      this.IsBusy = true;
      
      if (DoLongCheckThatWillNotThrowException())
      {
        this.DebugLogSuccess();
        
        this.IsBusy = false;
        return true;
      }
      else
      {
        this.ErrorLogFailure();
        
        this.IsBusy = false;
        return false;
      }
    }

This case is overly simplistic because there are only two return points, but imagine if there were four... or ten... or a hundred.

At some point I would want to use `try`/`finally` for the following reasons:

* Keep to DRY principles (especially as the number of exit points gets higher)
* If it turns out that I&#39;m wrong about my inner function not throwing an exception, then I want to make sure `this.Working` is set to `false`.

So hypothetically, given &lt;i&gt;performance concerns, maintainability, and DRY principles,&lt;/i&gt; for what number of exit points (especially if I &lt;i&gt;can&lt;/i&gt; assume that all inner exceptions are caught) do I want to incur whatever performance penalty is associated with `try`/`finally`?

&lt;b&gt;EDIT #2:&lt;/b&gt; I changed the name of `this.Working` to `this.IsBusy`. Sorry, forgot to mention this is multithreaded (though only one thread will ever actually call the method); other threads will be polling to see if the object is doing its work. The return value is merely success or failure for if the work went as expected.

Overhead of try/finally in C#?

I have a project that stores templates in a `\Templates` folder next to the DLLs and EXE.

I want to determine this file path at runtime, but using a technique that will work inside a unit test as well as in production (and I don&#39;t want to disable shadow-copying in NUnit!)

`Assembly.Location` is no good because it returns the shadow-copied assembly&#39;s path when running under NUnit.

`Environment.CommandLine` is also of limited use because in NUnit et al it returns the path to NUnit, not to my project.

`Assembly.CodeBase` looks promising, but it&#39;s a UNC path:

    file:///D:/projects/MyApp/MyApp/bin/debug/MyApp.exe

Now I *could* turn this into a local filesystem path using string manipulation, but I suspect there&#39;s a cleaner way of doing it buried in the .NET framework somewhere. Anyone know a recommended way of doing this?

(Throwing an exception if the UNC path is not a `file:///` URL is absolutely fine in this context)

How can I convert Assembly.CodeBase into a filesystem path in C#?

Is there a function in C# that returns *x* times of a given char or string? Or must I code it myself?

Is there a built-in function to repeat a string or char in .NET?

I&#39;ve got the basics of LINQ-to-SQL down, but I&#39;ve been struggling trying to get JOINs to work properly.  I&#39;d like to know how to convert the following to LINQ-to-SQL (ideally using method chaining, as that is my preferred format).

    SELECT      c.CompanyId, c.CompanyName,
                p.FirstName + &#39; &#39; + p.LastName as AccountCoordinator,
                p2.FirstName + &#39; &#39; + p2.LastName as AccountManager
    FROM        dbo.Companies c
    INNER JOIN  dbo.Persons p
    ON          c.AccountCoordinatorPersonId = p.PersonId
    INNER JOIN  dbo.Persons p2
    ON          c.AccountManagerPersonId = p2.PersonId


How do I convert multiple inner joins in SQL to LINQ?

I need a regex that will only find matches where the entire string matches my query.

For instance if I do a search for movies with the name &quot;Red October&quot; I only want to match on that exact title (case insensitive) but not match titles like &quot;The Hunt For Red October&quot;. Not quite sure I know how to do this. Anyone know?

Thanks!

How do I match an entire string with a regex?

Say I have an `System.String[]` type object. I can query the type object to determine if it is an array 

    Type t1 = typeof(System.String[]);
    bool isAnArray = t1.IsArray; // should be true

However how do I get a type  object of the array item from t1

    Type t2 = ....; // should be typeof(System.String)

How do I get the Array Item Type from Array Type in .net

I need to split a number into even parts for example:
  
   32427237 needs to become 324 272 37  
   103092501 needs to become 103 092 501

How does one go about splitting it and handling odd number situations such as a split resulting in these parts e.g. 123 456 789 0?


Splitting a string / number every Nth Character / Number?

Is there a way to find how many values an array has?  Detecting whether or not I&#39;ve reached the end of an array would also work.

How do I find the length of an array?

Okay, so I have a 2D array z[50][50] and z&#39;s size is therefore 50 * 50, but if I say z.length I only get 50 back. How do I get the real size of a 2D array?

Get the size of a 2D array

In C++ what is the difference (if any) between using char and char[1].

examples:

    struct SomeStruct
    {
       char x;
       char y[1];
    };


Do the same reasons follow for unsigned char?

Difference between char and char[1]

I use `in_array()` to check whether a value exists in an array like below,

    $a = array(&quot;Mac&quot;, &quot;NT&quot;, &quot;Irix&quot;, &quot;Linux&quot;);
    if (in_array(&quot;Irix&quot;, $a)) 
    {
        echo &quot;Got Irix&quot;;
    }
    
    //print_r($a);

but what about an multidimensional array (below) - how can I check that value whether it exists in the multi-array?

    $b = array(array(&quot;Mac&quot;, &quot;NT&quot;), array(&quot;Irix&quot;, &quot;Linux&quot;));
    
    print_r($b);

or I shouldn&#39;t be using `in_array()` when comes to the multidimensional array?

in_array() and multidimensional array

A [palindrome][1] is a word, phrase, number or other sequence of units that can be read the same way in either direction.

To check whether a word is a palindrome I get the char array of the word and compare the chars. I tested it and it seems to work. However I want to know if it is right or if there is something to improve. 

Here is my code:

    public class Aufg1 {
    	public static void main(String[] args) {
    		String wort = &quot;reliefpfpfeiller&quot;;
    		char[] warray = wort.toCharArray();	
    		System.out.println(istPalindrom(warray));		
    	}
    	
    	public static boolean istPalindrom(char[] wort){
    		boolean palindrom = false;
    		if(wort.length%2 == 0){
    			for(int i = 0; i &lt; wort.length/2-1; i++){
    				if(wort[i] != wort[wort.length-i-1]){
    					return false;
    				}else{
    					palindrom = true;
    				}
    			}
    		}else{
    			for(int i = 0; i &lt; (wort.length-1)/2-1; i++){
    				if(wort[i] != wort[wort.length-i-1]){
    					return false;
    				}else{
    					palindrom = true;
    				}
    			}
    		}
    		return palindrom;
    	}
    }


  [1]: http://en.wikipedia.org/wiki/Palindrome

Check string for palindrome

I have an array defined:

    int [,] ary;
    // ...
    int nArea = ary.Length; // x*y or total area

This is all well and good, but I need to know how wide this array is in the `x` and `y` dimensions individually. Namely, `ary.Length` might return 12 - but does that mean the array is 4 high and 3 wide, or 6 high and 2 wide?

How can I retrieve this information?

How do you get the width and height of a multi-dimensional array?

When working with matrices in R, one can put them side-by-side or stack them top of each other using cbind and rbind, respectively. What is the equivalent function for stacking matrices or arrays in other dimensions?

For example, the following creates a pair of 2x2 matrices, each having 4 elements:

    x = cbind(1:2,3:4)
    y = cbind(5:6,7:8)

What is the code to combine them into a 2x2x2 array with 8 elements?


What is R&#39;s multidimensional equivalent of rbind and cbind?

There is the following query results: (key1 and key2 could be any text)

    id   key1     key2     value

    1    fred     apple    2
    2    mary     orange   10
    3    fred     banana   7
    4    fred     orange   4
    5    sarah    melon    5
    ...


and I wish to store the data in a grid (maybe as an array) **looping** all the records like this:

             apple    orange   banana  melon
    fred        2        4         7     -
    mary        -        10        -     -
    sarah       -        -         -     5


In PHP this would be really easy, using associative arrays:
    
    $result[&#39;fred&#39;][&#39;apple&#39;] = 2;

But in JavaScript associative arrays like this doesn&#39;t work.
After reading tons of tutorial, all I could get was this:

    arr=[];
    arr[1][&#39;apple&#39;] = 2;

but `arr[&#39;fred&#39;][&#39;apple&#39;] = 2;` doesn&#39;t work.
I tried arrays of objects, but objects properties can&#39;t be free text.
The more I was reading tutorials, the more I got confused...

Any idea is welcome :)

Content Type	Original Author	Original Content on Stackoverflow
Question	izb	View Question on Stackoverflow
Solution 1 - C#	GendoIkari	View Answer on Stackoverflow
Solution 2 - C#	Brian Rasmussen	View Answer on Stackoverflow
Solution 3 - C#	Paul Williams	View Answer on Stackoverflow

How do I find the size of a 2D array?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

How do I recover/resynchronise after someone pushes a rebase or a reset to a published branch?

jQuery: value.attr is not a function

Attributions