How to remove duplicate values ​​from an array in php

php method to remove duplicate values ​​from an array: first create a PHP sample file; then define a set of arrays with duplicate values; then use the "array_unique(array)" function to remove duplicate values ​​in the array; and finally output Just delete the result.

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array_unique() function removes duplicate values ​​​​from the array. and returns the result array.

When the values ​​of several array elements are equal, only the first element is retained and the other elements are deleted.

The key names in the returned array remain unchanged.

Note: The retained array will retain the key type of the first array item.

Syntax

array_unique(array)

Parameters

array required. Specifies an array.

sortingtype

Optional. Specifies how array elements/items are compared. Possible values:

SORT_STRING - Default. Compare items as strings.

SORT_REGULAR - Sort each item in regular order (Standard ASCII, does not change type).

SORT_NUMERIC - Treat each item as a number.

SORT_LOCALE_STRING - Treat each item as a string, based on the current locale (can be changed via setlocale()).

Description

array_unique() first sorts the values ​​as strings, then only retains the first encountered key name for each value, and then ignores all subsequent key names. This does not mean that the first occurrence of the same value in an unsorted array will be preserved.

Technical details

Return value: Returns the filtered array.

PHP Version: 4.0.1

Change Log:

In PHP 5.2.10, the default value of sorttype is changed back to SORT_STRING.

In PHP 5.2.9, the default value of sorttype is changed to SORT_REGULAR. Prior to this release, the default value for sorttype was SORT_STRING.

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