Php/docs/language.operators.array
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 $b.
|
The + operator returns the right-hand array appended
to the left-hand array; for keys that exist in both arrays, the elements
from the left-hand array will be used, and the matching elements from the
right-hand array will be ignored.
<?php$a = array("a" => "apple", "b" => "banana");$b = array("a" => "pear", "b" => "strawberry", "c" => "cherry");$c = $a + $b; // Union of $a and $becho "Union of \$a and \$b: \n";var_dump($c);$c = $b + $a; // Union of $b and $aecho "Union of \$b and \$a: \n";var_dump($c);$a += $b; // Union of $a += $b is $a and $becho "Union of \$a += \$b: \n";var_dump($a);?>
When executed, this script will print the following:
Union of $a and $b:
array(3) {
["a"]=>
string(5) "apple"
["b"]=>
string(6) "banana"
["c"]=>
string(6) "cherry"
}
Union of $b and $a:
array(3) {
["a"]=>
string(4) "pear"
["b"]=>
string(10) "strawberry"
["c"]=>
string(6) "cherry"
}
Union of $a += $b:
array(3) {
["a"]=>
string(5) "apple"
["b"]=>
string(6) "banana"
["c"]=>
string(6) "cherry"
}
Elements of arrays are equal for the comparison if they have the same key and value.
Example #1 Comparing arrays
<?php$a = array("apple", "banana");$b = array(1 => "banana", "0" => "apple");var_dump($a == $b); // bool(true)var_dump($a === $b); // bool(false)?>
