Add:

    using System.Linq;

to the top of your file. 

And then:

    Car[] carList = ...
    var carMake = 
        from item in carList
        where item.Model == &quot;bmw&quot; 
        select item.Make;

or if you prefer the fluent syntax:

    var carMake = carList
        .Where(item =&gt; item.Model == &quot;bmw&quot;)
        .Select(item =&gt; item.Make);

Things to pay attention to:

* The usage of `item.Make` in the `select` clause instead if `s.Make` as in your code.
* You have a whitespace between `item` and `.Model` in your `where` clause

Suppose that I have the following code snippet:

    var data=new List&lt;string&gt;(){&quot;One&quot;,&quot;Two&quot;,&quot;Three&quot;};
    for(int i=0 ; i&lt;data.Count ; i++){
      if(data[i]==&quot;One&quot;){
        data.RemoveAt(i);
      }
    }

The following code throws exception.

My question is what is the best way to avoid this exception and to remove the element while looping?

C# List - Removing items while looping / iterating

Is it possible to replace all carriage returns in a string with the `.replace` function?  I&#39;ve found quite a few complex functions to do it, but was wondering if it could be simplified with just a regex through `.replace`?

Thanks!

Is it possible to replace all carriage returns in a string via .replace?

I would like to know how can I query an array of objects. For example I have an array object like CarList. So CarList[0] would return me the object Car. Car has properties Model and Make. Now, I want to use linq to query the array CarList to get the Make of a Car whose Model is say &quot;bmw&quot;. I tried the following

    var carMake = from item in CarList where item .Model == &quot;bmw&quot; select s.Make;

I get the error 

&gt; Could not find an implementation of the query pattern for source type CarList[]

I cannot change CarList from array to something like List&lt;&gt; since CarList is retured to me as array from a webservice.


Kindly let me know how this can be solved. Would be great if you can explain using C# code.

Thanks in advance.

Query an object array using linq

I would like to know how can I query an array of objects. For example I have an array object like CarList. So CarList[0] would return me the object Car. Car has properties Model and Make. Now, I want to use linq to query the array CarList to get the Make of a Car whose Model is say "bmw". I tried the following
<pre><code class="hljs language-csharp">var carMake = from item in CarList where item .Model == "bmw" select s.Make;
</code></pre>
I get the error
> Could not find an implementation of the query pattern for source type CarList[]
I cannot change CarList from array to something like List&#x3C;> since CarList is retured to me as array from a webservice.
Kindly let me know how this can be solved. Would be great if you can explain using C# code.
Thanks in advance.

I am receiving the error shown in the title from a LINQ query that includes two tables from two different edmx files. Here is the query:

    var query = (from a in db1.Table1
               join b in db1.Table2 on a.Id equals b.Id
               orderby a.Status
               where b.Id == 1 &amp;&amp; a.Status == &quot;new&quot;
               select new
               {
                   Id = a.Id,
                   CompanyId = (from c in db2.Company
                                where s.Id == a.Id
                                select
                                new { c.CompanyId })
               });

`db1` and `db2` are contexts that are associated with two different edmx files. How can I overcome this error?

Error: &quot;The specified LINQ expression contains references to queries that are associated with different contexts&quot;

From what I&#39;ve read about Tasks, the following code should cancel the currently executing task without throwing an exception. I was under the impression that the whole point of task cancellation was to politely &quot;ask&quot; the task to stop without aborting threads.

The output from the following program is:

&gt; Dumping exception
&gt; 
&gt; [OperationCanceledException]
&gt; 
&gt; Cancelling and returning last calculated prime.

I am trying to avoid any exceptions when cancelling. How can I accomplish this?

    void Main()
    {
        var cancellationToken = new CancellationTokenSource();
    	
    	var task = new Task&lt;int&gt;(() =&gt; {
    		return CalculatePrime(cancellationToken.Token, 10000);
    	}, cancellationToken.Token);
    	
    	try
        {
    	    task.Start();
            Thread.Sleep(100);
            cancellationToken.Cancel();
            task.Wait(cancellationToken.Token);    		
    	}
        catch (Exception e)
        {
            Console.WriteLine(&quot;Dumping exception&quot;);
            e.Dump();
    	}
    }

    int CalculatePrime(CancellationToken cancelToken, object digits)
    {  
    	int factor; 
    	int lastPrime = 0;
    
     	int c = (int)digits;
    	
    	for (int num = 2; num &lt; c; num++)
        { 
            bool isprime = true;
            factor = 0; 
 		
            if (cancelToken.IsCancellationRequested)
            {
                Console.WriteLine (&quot;Cancelling and returning last calculated prime.&quot;);
                //cancelToken.ThrowIfCancellationRequested();
                return lastPrime;
            }
    		
            // see if num is evenly divisible 
            for (int i = 2; i &lt;= num/2; i++)
            { 
                if ((num % i) == 0)
                {             
                    // num is evenly divisible -- not prime 
                    isprime = false; 
                    factor = i; 
                }
            } 
     	
            if (isprime)
            {
                lastPrime = num;
            }
        }
    	
        return lastPrime;
    }

Cancelling a Task is throwing an exception

I am newbie in .net. I am doing compression and decompression string in C#. There is a XML and I am converting in string and after that I am doing compression and decompression.There is no compilation error in my code except when I decompression my code and return my string, its returning only half of the XML.

Below is my code, please correct me where I am wrong.

Code:

    class Program
    {
        public static string Zip(string value)
        {
            //Transform string into byte[]  
            byte[] byteArray = new byte[value.Length];
            int indexBA = 0;
            foreach (char item in value.ToCharArray())
            {
                byteArray[indexBA++] = (byte)item;
            }

            //Prepare for compress
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            System.IO.Compression.GZipStream sw = new System.IO.Compression.GZipStream(ms, System.IO.Compression.CompressionMode.Compress);

            //Compress
            sw.Write(byteArray, 0, byteArray.Length);
            //Close, DO NOT FLUSH cause bytes will go missing...
            sw.Close();

            //Transform byte[] zip data to string
            byteArray = ms.ToArray();
            System.Text.StringBuilder sB = new System.Text.StringBuilder(byteArray.Length);
            foreach (byte item in byteArray)
            {
                sB.Append((char)item);
            }
            ms.Close();
            sw.Dispose();
            ms.Dispose();
            return sB.ToString();
        }
    
        public static string UnZip(string value)
        {
            //Transform string into byte[]
            byte[] byteArray = new byte[value.Length];
            int indexBA = 0;
            foreach (char item in value.ToCharArray())
            {
                byteArray[indexBA++] = (byte)item;
            }

            //Prepare for decompress
            System.IO.MemoryStream ms = new System.IO.MemoryStream(byteArray);
            System.IO.Compression.GZipStream sr = new System.IO.Compression.GZipStream(ms,
                System.IO.Compression.CompressionMode.Decompress);

            //Reset variable to collect uncompressed result
            byteArray = new byte[byteArray.Length];

            //Decompress
            int rByte = sr.Read(byteArray, 0, byteArray.Length);

            //Transform byte[] unzip data to string
            System.Text.StringBuilder sB = new System.Text.StringBuilder(rByte);
            //Read the number of bytes GZipStream red and do not a for each bytes in
            //resultByteArray;
            for (int i = 0; i &lt; rByte; i++)
            {
                sB.Append((char)byteArray[i]);
            }
            sr.Close();
            ms.Close();
            sr.Dispose();
            ms.Dispose();
            return sB.ToString();
        }
        
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(@&quot;D:\RSP.xml&quot;);
            string val = doc.ToString(SaveOptions.DisableFormatting);
            val = Zip(val);
            val = UnZip(val);
        }
    } 

My XML size is 63KB.

Compression/Decompression string with C#

I&#39;m doing the mvcmusicstore practice tutorial. I noticed something when creating the scaffold for the album manager (add delete edit).

I want to write code elegantly, so i&#39;m looking for the clean way to write this.

FYI i&#39;m making the store more generic:

Albums = Items

Genres = Categories

Artist = Brand

Here is how the index is retrieved (generated by MVC):
    
    var items = db.Items.Include(i =&gt; i.Category).Include(i =&gt; i.Brand);

Here is how the item for delete is retrieved:

    Item item = db.Items.Find(id);

The first one brings back all the items and populates the category and brand models inside the item model. The second one, doesn&#39;t populate the category and brand.

How can i write the second one to do the find AND populate whats inside (preferably in 1 line)... theoretically - something like:

    Item item = db.Items.Find(id).Include(i =&gt; i.Category).Include(i =&gt; i.Brand);


C# Entity-Framework: How can I combine a .Find and .Include on a Model Object?

I have a numpy array containing:

    [1, 2, 3]

I want to create an array containing:

    [1, 2, 3, 1]

That is, I want to add the first element on to the end of the array.

I have tried the obvious:

    np.concatenate((a, a[0]))

But I get an error saying `ValueError: arrays must have same number of dimensions`

I don&#39;t understand this - the arrays are both just 1d arrays.

Add single element to array in numpy

Say I&#39;ve got this

&lt;!-- language: lang-js --&gt;

    imageList = [100,200,300,400,500];

Which gives me

`[0]100 [1]200` etc.

Is there any way in JavaScript to return the index with the value?

I.e. I want the index for **200**, I get returned **1**.

How to find the array index with a value?

I&#39;ve got an array:

    myArray = [{&#39;id&#39;:&#39;73&#39;,&#39;foo&#39;:&#39;bar&#39;},{&#39;id&#39;:&#39;45&#39;,&#39;foo&#39;:&#39;bar&#39;}, etc.]

I&#39;m unable to change the structure of the array. I&#39;m being passed an id of `45`, and I want to get `&#39;bar&#39;` for that object in the array. 

How do I do this in JavaScript or using jQuery?


Find object by id in an array of JavaScript objects

How do I get the second dimension of an array if I don&#39;t know it? `array.length` gives only the first dimension. 

For example, in

    public class B {
    	public static void main(String [] main){
    		int [] [] nir = new int [2] [3];
    		System.out.println(nir.length);
    	}
    }

how would I get the value of the second dimension of `nir`, which is 3. 

Thanks 

Getting the length of two-dimensional array

The function I am using now to check this is the following:

    function inArray(needle,haystack)
    {
    	var count=haystack.length;
    	for(var i=0;i&lt;count;i++)
    	{
    		if(haystack[i]===needle){return true;}
    	}
    	return false;
    }

It works. What I&#39;m looking for is whether there is a better way of doing this.

Content Type	Original Author	Original Content on Stackoverflow
Question	Derin	View Question on Stackoverflow
Solution 1 - C#	Darin Dimitrov	View Answer on Stackoverflow

Query an object array using linq

C# Problem Overview

C# Solutions

Solution 1 - C#

Is it possible to replace all carriage returns in a string via .replace?

C# List - Removing items while looping / iterating

Attributions