C# 0 The Complete Reference

y

 will be set to 11. This is because 

x

 is first incremented and then its value is 

returned. However, if the code is written as

x = 10;

y = x++;

then

 y

 will be set to 10. In this case, the value of 

x

 is first obtained, 

x

 is incremented, and 

then the original value of 

x

 is returned. In both cases, 

x

 is still set to 11. The difference is 

what is returned by the operation.

There are significant advantages in being able to control when the increment or decrement 

operation takes place. Consider the following program, which generates a series of numbers:

// Demonstrate the difference between prefix and

// postfix forms of ++.

using System;

class PrePostDemo {

  static void Main() {

    int x, y;

    int i;

    x = 1;

    Console.WriteLine("Series generated using y = x + x++;");

    for(i = 0; i < 10; i++) {

      y = x + x++; // postfix ++

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      Console.WriteLine(y + " ");

    }

    Console.WriteLine();

    x = 1;

    Console.WriteLine("Series generated using y = x + ++x;");

    for(i = 0; i < 10; i++) {

      y = x + ++x; // prefix ++

      Console.WriteLine(y + " ");

    }

    Console.WriteLine();

  }

}

The output is shown here:

Series generated using y = x + x++;

2

4

6

8

10

12

14

16

18

20

Series generated using y = x + ++x;

3

5

7

9

11

13

15

17

19

21

As the output confirms, the statement

y = x + x++;

adds the original value of