Russian Ukraine English
Catalog RSS


Incrementing/Decrementing Operators

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

Table 10-4. Increment/decrement Operators

ExampleNameEffect
++$aPre-incrementIncrements $a by one, then returns $a.
$a++Post-incrementReturns $a, then increments $a by one.
--$aPre-decrementDecrements $a by one, then returns $a.
$a--Post-decrementReturns $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"; ?>      

Led