in_array
Checks whether a value exists in an array.
Available since: PHP 4
Syntax
in_array(mixed $needle, array $haystack, bool $strict = false): boolParameters
| Parameter | Type | Description |
|---|---|---|
| $needle | mixed | The value to look for. |
| $haystack | array | The array to search in. |
| $strict | bool | If `true`, the type is compared as well. |
Return value
bool`true` if the value is found, `false` otherwise.
Examples
Looking for a value:
<?php
var_dump(in_array('b', ['a', 'b', 'c']));
var_dump(in_array('z', ['a', 'b', 'c']));Output:
bool(true)
bool(false)Without strict mode the string '1' equals the number 1:
<?php
var_dump(in_array('1', [1, 2, 3]));
var_dump(in_array('1', [1, 2, 3], true));Output:
bool(true)
bool(false)Notes
Pass true as the third argument: loose comparison produces surprising matches. The function searches values; use array_key_exists() to check for a key.
See also
- array_search — Searches an array for a value and returns its key.
- count — Returns the number of elements in an array.
Related recipes
In the tutorial
- Arrays — Lists and associative arrays in PHP — creating, changing, iterating and useful functions.