The increment/decrement operators are used to increment/decrement a variable's value and they only affect numbers and strings.
| Operator | Name | Description |
|---|---|---|
| ++$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. |
<?php $a = 5; echo ++$a; // Outputs: 6 echo $a; // Outputs: 6 $a = 5; echo $a++; // Outputs: 5 echo $a; // Outputs: 6 $a = 5; echo --$a; // Outputs: 4 echo $a; // Outputs: 4 $a = 5; echo $a--; // Outputs: 5 echo $a; // Outputs: 4 ?>