PHP array_unique() Function

Last Updated : 17 Mar 2025

The array_unique( ) function is an inbuilt function of PHP and it is used to remove duplicate values from an array. This function was introduced in 4.0.1

Syntax

Parameters

Parameter	Description	Is compulsory
array1	The input array.	compulsory
sort_flags	The optional second parameter sort_flags may be used to modify the sorting behavior using these values: Sorting type flags SORT_REGULAR - match items normally SORT_NUMERIC - match items numerically SORT_STRING - match items as strings SORT_LOCALE_STRING - match items as strings, based on the current locale.	Optional

Return

The array_unique( ) function returns the filtered array.

Example 1

Output:

Array
(
    [a] => zee
    [c] =>aajtak
    [d] =>ndtv
)

Example 2

Output:

Array
(
    [0] => java
    [1] =>php
    [3] => python
    [4] => html
)

Example 3

Output:

Array
(
    [a] =>abhijeet
    [b] =>arijit
)

Example 4

Output:

Array
(
    [a] => dell
    [0] =>hp
    [1] =>leneovo
)

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