Question

What is Decrement Operator in JAVA?

Answer 1

It is used to decrement the value of an operand by 1. The operator is represented by a pair of minus operators (--). The operator can be applied before or after an operand.

Pre-decrement Operator: If a decrement operator is written before (prefix) the operand is known as pre-decrement. In such a case, the value is first decremented by 1 and then used for the computing purpose.

Syntax:

1. --operand  

Example: Suppose x=9, then the value of --x will be 8.

Post-decrement Operator: If a decrement operator is written after (postfix) the operand is known as post-decrement. In such a case, the value is first used and then decrements by 1.

Syntax:

1. operand--  

Example: Suppose x=11, then the value of x-- will be 10.

Let's use the pre-decrement and post-decrement operators in a Java program.

PrePostDecrementExample.java

1. public class PrePostDecrementExample   
2. {  
3. public static void main(String args[])  
4. {  
5. int i = 10;  
6. i--;  
7. //prints 19  
8. System.out.println(i);  
9. --i;                 
10. //prints 18  
11. System.out.println(i);  
12. //prints 17  
13. System.out.println(--i);  
14. //prints 17  
15. System.out.println(i--);  
16. //prints 16  
17. System.out.println(i);  
18. }  
19. }  

Output:

19
18
17
17
16