Php/docs/function.array-unique
array_unique
(PHP 4 >= 4.0.1, PHP 5, PHP 7)
array_unique — Removes duplicate values from an array
Description
array_unique
( array $array
[, int $flags
= SORT_STRING
] ) : array
Takes an input array
and returns a new array
without duplicate values.
Note that keys are preserved. If multiple elements compare equal under
the given flags
, then the key and value of
the first equal element will be retained.
Note:
Two elements are considered equal if and only if
(string) $elem1 === (string) $elem2
i.e. when the string representation is the same, the first element will be used.
Parameters
array
The input array.
flags
The optional second parameter
flags
may be used to modify the sorting behavior using these values:Sorting type flags:
SORT_REGULAR
- compare items normally (don't change types)SORT_NUMERIC
- compare items numericallySORT_STRING
- compare items as stringsSORT_LOCALE_STRING
- compare items as strings, based on the current locale.
Return Values
Returns the filtered array.
Changelog
Version | Description |
---|---|
7.2.0 | If flags is SORT_STRING ,
formerly |
Examples
Example #1 array_unique() example
<?php$input = array("a" => "green", "red", "b" => "green", "blue", "red");$result = array_unique($input);print_r($result);?>
The above example will output:
Array ( [a] => green [0] => red [1] => blue )
Example #2 array_unique() and types
<?php$input = array(4, "4", "3", 4, 3, "3");$result = array_unique($input);var_dump($result);?>
The above example will output:
array(2) { [0] => int(4) [2] => string(1) "3" }
Notes
Note:
Note that array_unique() is not intended to work on multi dimensional arrays.