C Language Operators Increment / Decrement
Example
The increment and decrement operators exist in prefix and postfix form.
int a = 1;
int b = 1;
int tmp = 0;
tmp = ++a; /* increments a by one, and returns new value; a == 2, tmp == 2 */
tmp = a++; /* increments a by one, but returns old value; a == 3, tmp == 2 */
tmp = --b; /* decrements b by one, and returns new value; b == 0, tmp == 0 */
tmp = b--; /* decrements b by one, but returns old value; b == -1, tmp == 0 */
Note that arithmetic operations do not introduce sequence points, so certain expressions with ++ or -- operators may introduce undefined behaviour.
