PHP Manual
Prev |  | Next

# array_unique

(PHP 4 )

array_unique -- Removes duplicate values from an array

## Description

``array array_unique` (array array)`

array_unique() takes input `array` and returns a new array without duplicate values.

Note that keys are preserved. array_unique() will keep the first key encountered for every value, and ignore all following keys.

> Note: Two elements are considered equal if and only if `(string) $elem1 === (string) $elem2`. In words: when the string representation is the same.

> The first element will be used.

Warning
This was broken in PHP 4.0.4!

Example 1. array_unique() example
    $input = array ("a" => "green", "red", "b" => "green", "blue", "red");
    $result = array_unique ($input);
    print_r($result);
    // this will output :
    //Array
    //(
    //    [a] => green
    //    [0] => red
    //    [1] => blue
    //)

Example 2. array_unique() and types
    $input = array (4,"4","3",4,3,"3");
    $result = array_unique ($input);
    var_dump($result);

    /* output:
    array(2) {
       [0]=>
       int(4)
       [1]=>
       string(1) "3"
    }
    */

Prev | Home | Next
array_sum | Up | array_unshift