Increment and Decrement Operator in C

There are two such operators.

1. Increment operator is represented by ‘++’. This operator adds 1 to the value with which it is written. For example, y++ and ++y will add 1 to the ‘y’.
2. Decrement operator is represented by ‘–’.This operator subtracts 1 from the value with which it is written. For example, y–, and –y will subtract 1 from the ‘y’.

Both operators are used in two ways:

Postfix: a++ increases the value of ‘a’ by 1. a—subtracts 1 from that value.

Prefix: ++a increases the value of ‘a’ by 1.–a decreases the value of a by 1.

Difference between prefix and postfix in C

In a++, we get the original value of ‘a’ first, then it will get incremented.  But ++a first increases the value of ‘a’ by 1 and returns the same incremented value of ‘a’. The same as with a– and –a.

Example

#include<stdio.h>
int main()
{
            int a=100;
            int b=200;
            int c=300;
            int d=400;
            printf("value of a++ = %d\n",a++);
             printf("value of ++b = %d\n",++b);
             printf("value of c-- = %d\n",c--);
             printf("value of --d = %d\n",--d);
}

Output

In a++, ‘100’ is printed, and then the value gets incremented.

In ++b, ‘201’ is printed because 1 is added to 200, and it gets displayed.

The same occurs with variables c and d.