C# 0 The Complete Reference

PART I

C h a p t e r   8 :  

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PART IPART I

Use ref

The

ref

 parameter modifier causes C# to create a call-by-reference, rather than a call-by-

value. The 

ref

 modifier is specified when the method is declared and when it is called. Let’s 

begin with a simple example. The following program creates a method called 

Sqr( )

 that 

returns in-place the square of its integer argument. Notice the use and placement of 

ref

.

// Use ref to pass a value type by reference.

using System;

class RefTest {

  // This method changes its argument. Notice the use of ref.

  public void Sqr(ref int i) {

    i = i * i;

  }

}

class RefDemo {

  static void Main() {

    RefTest ob = new RefTest();

    int a = 10;

    Console.WriteLine("a before call: " + a);

    ob.Sqr(ref a); // notice the use of ref

    Console.WriteLine("a after call: " + a);

  }

}

Notice that 

ref

 precedes the entire parameter declaration in the method and that it precedes 

the argument when the method is called. The output from this program, shown here, confirms 

that the value of the argument,