Increment/Decrement Operator

Question

what is the difference between these two types of operator....

Answer 1

One lowers the value of a variable by one, the other one increases it.
++x is the same as (x = x + 1)
--x is the same as (x = x - 1)

The difference between x++ and ++x is that ++x first increases the value of x and then gives back it's value and x++ works the other way around.
Example:
int x = 5;
int y = ++x; /* ++x -> x is now 6, so y is also 6 */
x = 5;
y = x++; /* x is 6 again, but y is now 5 */

Btw, y = x++ has the same effect as same as writing y = ((x = x + 1) - 1), but this'll probably confuse you more than it'll help.