Incrementing/Decrementing Operators

PHP supports C-style pre- and post-increment and decrement operators.

Table 10-4. 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 echo "<h3>Postincrement</h3>"; $a = 5; echo "Should be 5: " . $a++ . "<br>\n"; echo "Should be 6: " . $a . "<br>\n";  echo "<h3>Preincrement</h3>"; $a = 5; echo "Should be 6: " . ++$a . "<br>\n"; echo "Should be 6: " . $a . "<br>\n";  echo "<h3>Postdecrement</h3>"; $a = 5; echo "Should be 5: " . $a-- . "<br>\n"; echo "Should be 4: " . $a . "<br>\n";  echo "<h3>Predecrement</h3>"; $a = 5; echo "Should be 4: " . --$a . "<br>\n"; echo "Should be 4: " . $a . "<br>\n"; ?>