Comparison operators, as their name implies, allow you to compare two values. You may also be interested in viewing the type comparison tables, as they show examples of various type related comparisons.
Table 10-4. Comparison Operators
| Example | Name | Result |
|---|---|---|
| $a == $b | Equal | TRUE if $a is equal to $b. |
| $a === $b | Identical | TRUE if $a is equal to $b, and they are of the same type. (PHP 4 only) |
| $a != $b | Not equal | TRUE if $a is not equal to $b. |
| $a <> $b | Not equal | TRUE if $a is not equal to $b. |
| $a !== $b | Not identical | TRUE if $a is not equal to $b, or they are not of the same type. (PHP 4 only) |
| $a < $b | Less than | TRUE if $a is strictly less than $b. |
| $a > $b | Greater than | TRUE if $a is strictly greater than $b. |
| $a <= $b | Less than or equal to | TRUE if $a is less than or equal to $b. |
| $a >= $b | Greater than or equal to | TRUE if $a is greater than or equal to $b. |
Another conditional operator is the "?:" (or ternary) operator, which operates as in C and many other languages.
<?php
// Example usage for: Ternary Operator
$action = (empty($_POST['action'])) ? 'default' : $_POST['action'];
// The above is identical to this if/else statement
if (empty($_POST['action'])) {
$action = 'default';
} else {
$action = $_POST['action'];
}
?> |
See also strcasecmp(), strcmp(), and the manual section on Types.