C# 0 The Complete Reference

PART I

C h a p t e r   1 9 :  

L I N Q  

547

PART IPART I

    // Create a query that obtains only positive numbers.

    var posNums = from n in nums

                  where n > 0

                  select n;

    Console.Write("The positive values in nums: ");

    // Execute the query and display the results.

    foreach(int i in posNums) Console.Write(i + " ");

    Console.WriteLine();

  }

}

This program produces the following output:

The positive values in nums: 1 3 5

As you can see, only the positive values in the 

nums

 array are displayed. Although quite 

simple, this program demonstrates the key features of LINQ. Let’s examine it closely.

The first thing to notice in the program is the 

using

 directive:

using System.Linq;

To use the LINQ features, you must include the 

System.Linq

 namespace.

Next, an array of