C# 0 The Complete Reference

PART I

C h a p t e r   1 9 :  

L I N Q  

579

PART IPART I

The minimum value is 1

The maximum value is 5

The first value is 3

The last value is 4

The sum is 15

The average is 3

All values are greater than zero.

At least one value is even.

The array contains 3.

You can also use the query-related extension methods within a query based on the C# 

query syntax. In fact, it is quite common to do so. For example, this program uses 

Average( )

to obtain a sequence that contains only those values that are less than the average of the 

values in an array.

// Use Average() with the query syntax.

using System;

using System.Linq;

class ExtMethods2 {

  static void Main() {

    int[] nums =  { 1, 2, 4, 8, 6, 9, 10, 3, 6, 7 };

    var ltAvg = from n in nums

                let x = nums.Average()

                where n < x

                select n;

    Console.WriteLine("The average is " + nums.Average());

    Console.Write("These values are less than the average: ");

    // Execute the query and display the results.

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

    Console.WriteLine();

  }

}

The output is shown here:

The average is 5.6

These values are less than the average: 1 2 4 3

Pay special attention to the query:

    var ltAvg = from n in nums

                let x = nums.Average()

                where n < x

                select n;

Notice in the