Page 122 - computer science (868) class 11
P. 122
Operator Meaning Description Usage Example
Unary ++ Unary Increment It is used to Prefix Unary int a=5, b;
increase the value Increment – b = ++a;
of the operand by Used before the Ans. 6
1. operand (5+1=6)
It works the same Postfix Unary int a=5, b;
as val=val+1; Increment – Used
after the operand b = a++;
Ans. 5
Unary -- Unary Decrement It is used to Prefix Unary int a=6, b;
decrease the value Decrement – b = --a;
of the operand by Used before the
1. operand Ans. 5
(6-1=5)
It works the same Postfix Unary
as val=val-1; Decrement – int a=6, b;
Used after the b = a --;
operand
Ans. 6
Let us understand the prefix and postfix increment and decrement operators with the help of some examples.
The prefix increment/decrement operator works on the principle of ‘Change Before Action’. Given below is the example
of the prefix increment operator. Here, an increment by 1 is executed first and then the value is used.
int a=5, b;
System.out.println("a: " +a);
b=++a;
System.out.println("a: " +a+ " and b: " +b);
Output:
a: 5
a: 6 and b: 6
Given below is the example of the prefix decrement operator. Here, the decrement by 1 is executed first and then the
value is used.
int a=5, b;
System.out.println("a: " +a);
b=--a;
System.out.println("a: " +a+ " and b: " +b);
Output:
a: 5
a: 4 and b: 4
The postfix increment/decrement operator works on the principle of ‘Change After Action’.
Given below is an example of the postfix increment operator. Here, the value is used first and then an increment by 1
is done on the given value.
120120 Touchpad Computer Science-XI

