Array Operators

Example Name Result
$a + $b Union Union of $a and $b.
$a == $b Equality TRUE if $a and $b have the same key/value
pairs.
$a === $b Identity TRUE if $a and $b have the same key/value
pairs in the same order and of the same types.
$a != $b Inequality TRUE if $a is
not equal to $b.
$a <> $b Inequality TRUE if $a is
not equal to $b.
$a !== $b Non-identity TRUE if $a is
not identical to $b.

The + operator returns the right-hand array appended to the left-hand array; for keys that exist in both arrays, the elements from the left-hand array will be used, and the matching elements from the right-hand array will be ignored.
var_dump — Dumps information about a variable.

<?php
$a = array("a" => "apple", "b" => "banana");
$b = array("a" => "pear", "b" => "strawberry", "c" => "cherry");

$c = $a + $b; // Union of $a and $b
echo "Union of \$a and \$b: \n";
var_dump($c);

$c = $b + $a; // Union of $b and $a
echo "Union of \$b and \$a: \n";
var_dump($c);

?>