Comparison Operators
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.
<?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'];
}
?>
The expression (expr1) ? (expr2) : (expr3) evaluates to
expr2 if expr1 evaluates to TRUE, and expr3 if expr1 evaluates
to FALSE.
See also strcasecmp(), strcmp(), Array operators, and the
manual section on Types.
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