Initial Value of x Expression Final Value of y Final Value of x
5 y = x++ 5 6
5 y = ++x 6 6
5 y = x-- 5 4
5 y = --x 4 4
For example:
x = 42;
y = ++x;
y is set to 43, because the increment occurs before x is assigned to y. Thus, the line
y = ++x;
is the equivalent of these two statements:
x = x + 1;
y = x;
However, when written like this,
x = 42;
y = x++;
the value of x is obtained before the increment operator is executed, so the value of y is 42.
In both cases x is set to 43. The line
y = x++;
is the equivalent of these two statements:
y = x;
x = x + 1;
The following program demonstrates the increment operator.
public class Main {
public static void main(String args[]) {
int a = 1;
int b = 2;
int c = ++b;
int d = a++;
System.out.println("a = " + a);
System.out.println("b = " + b);
System.out.println("c = " + c);
System.out.println("d = " + d);
}
}
The output of this program follows:
a = 2
b = 3
c = 3
d = 1