C# 0 The Complete Reference

PART I

C h a p t e r   1 5 :  

D e l e g a t e s ,   E v e n t s ,   a n d   L a m b d a   E x p r e s s i o n s  

417

PART IPART I

Here is an example that uses a statement lambda to compute and return the factorial of 

an

int

 value:

// Demonstrate a statement lambda.

using System;

// IntOp takes one int argument and returns an int result.

delegate int IntOp(int end);

class StatementLambdaDemo {

  static void Main() {

    // A statement lambda that returns the factorial

    // of the value it is passed.

    IntOp fact = n => {

                         int r = 1;

                         for(int i=1; i <= n; i++)

                           r = i * r;

                         return r;

                      };

    Console.WriteLine("The factorial of 3 is " + fact(3));

    Console.WriteLine("The factorial of 5 is " + fact(5));

  }

}

The output is shown here:

The factorial of 3 is 6

The factorial of 5 is 120

In the program, notice that the statement lambda declares a variable called