Incrementing/Decrementing Operators
PHP supports C-style pre- and post-increment and decrement
operators.
Table 10-5. Increment/decrement Operators
Example | Name | Effect |
---|
++$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.
Example 10-1. Arithmetic Operations on Character Variables
<?php $i = 'W'; for($n=0; $n<6; $n++) echo ++$i . "\n";
/* Produces the output similar to the following:
X Y Z AA AB AC
*/ ?>
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