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. |
Try this example:
<?php
echo “<h3>Postincrement</h3>”;
$a = 5;
echo “Should be 5: ” . $a++ . “<br />
“;
echo “Should be 6: ” . $a . “<br />
“;
echo “<h3>Preincrement</h3>”;
$a = 5;
echo “Should be 6: ” . ++$a . “<br />
“;
echo “Should be 6: ” . $a . “<br />
“;
echo “<h3>Postdecrement</h3>”;
$a = 5;
echo “Should be 5: ” . $a– . “<br />
“;
echo “Should be 4: ” . $a . “<br />
“;
echo “<h3>Predecrement</h3>”;
$a = 5;
echo “Should be 4: ” . –$a . “<br />
“;
echo “Should be 4: ” . $a . “<br />
“;
?>
Output:
Postincrement
Should be 5: 5
Should be 6: 6
Preincrement
Should be 6: 6
Should be 6: 6
Postdecrement
Should be 5: 5
Should be 4: 4
Predecrement
Should be 4: 4
Should be 4: 4