PHP supports C-style pre- and post-increment and decrement operators.
Note: The increment/decrement operators do not affect boolean values. Decrementing NULL values has no effect too, but incrementing them results in 1.
Table 15-6. Increment/decrement Operators
|++$a||Pre-increment||Increments $a by one, then returns $a.|
|$a++||Post-increment||Returns $a, then increments $a by one.|
|--$a||Pre-decrement||Decrements $a by one, then returns $a.|
|$a--||Post-decrement||Returns $a, then decrements $a by one.|
Here's a simple example script:
PHP follows Perl's convention when dealing with arithmetic operations on character variables and not C's. For example, in Perl 'Z'+1 turns into 'AA', while in C 'Z'+1 turns into '[' ( ord('Z') == 90, ord('[') == 91 ). Note that character variables can be incremented but not decremented and even so only plain ASCII characters (a-z and A-Z) are supported.
Incrementing or decrementing booleans has no effect.