<Li> The post-increment and post-decrement operators increase (or decrease) the value of their operand by 1, but the value of the expression is the operand's original value prior to the increment (or decrement) operation . </Li> <P> In languages where increment / decrement is not an expression (e.g. Go), only one version is needed (in the case of Go, post operators only). </P> <P> Since the increment / decrement operator modifies its operand, use of such an operand more than once within the same expression can produce undefined results . For example, in expressions such as x - + + x, it is not clear in what sequence the subtraction and increment operations should be performed . Such expressions generally invoke undefined behavior, and should be avoided . </P> <P> The following C code fragment illustrates the difference between the pre and post increment and decrement operators: </P>

How increment and decrement operators work in c