Tutorials Exercises Get Certified Services Menu
Log in
Sign Up Spaces Bootcamps

PHP Tutorial

PHP HOME PHP Intro PHP Install PHP Syntax PHP Comments PHP Variables PHP Echo / Print PHP Data Types PHP Strings PHP Numbers PHP Math PHP Constants PHP Operators PHP If...Else...Elseif PHP Switch PHP Loops PHP Functions PHP Arrays PHP Superglobals PHP RegEx

PHP Forms

PHP Form Handling PHP Form Validation PHP Form Required PHP Form URL/E-mail PHP Form Complete

PHP Advanced

PHP Date and Time PHP Include PHP File Handling PHP File Open/Read PHP File Create/Write PHP File Upload PHP Cookies PHP Sessions PHP Filters PHP Filters Advanced PHP Callback Functions PHP JSON PHP Exceptions


PHP What is OOP PHP Classes/Objects PHP Constructor PHP Destructor PHP Access Modifiers PHP Inheritance PHP Constants PHP Abstract Classes PHP Interfaces PHP Traits PHP Static Methods PHP Static Properties PHP Namespaces PHP Iterables

MySQL Database

MySQL Database MySQL Connect MySQL Create DB MySQL Create Table MySQL Insert Data MySQL Get Last ID MySQL Insert Multiple MySQL Prepared MySQL Select Data MySQL Where MySQL Order By MySQL Delete Data MySQL Update Data MySQL Limit Data


PHP XML Parsers PHP SimpleXML Parser PHP SimpleXML - Get PHP XML Expat PHP XML DOM



PHP Examples

PHP Examples PHP Compiler PHP Quiz PHP Exercises PHP Certificate

PHP Reference

PHP Overview PHP Array PHP Calendar PHP Date PHP Directory PHP Error PHP Exception PHP Filesystem PHP Filter PHP FTP PHP JSON PHP Keywords PHP Libxml PHP Mail PHP Math PHP Misc PHP MySQLi PHP Network PHP Output Control PHP RegEx PHP SimpleXML PHP Stream PHP String PHP Variable Handling PHP XML Parser PHP Zip PHP Timezones

PHP array_unique() Function

❮ PHP Array Reference


Remove duplicate values from an array:

Try it Yourself »

Definition and Usage

The array_unique() function removes duplicate values from an array. If two or more array values are the same, the first appearance will be kept and the other will be removed.

Note: The returned array will keep the first array item's key type.


array_unique(array, sorttype)

Parameter Values

Parameter Description
array Required. Specifying an array
sorttype Optional. Specifies how to compare the array elements/items. Possible values:
  • SORT_STRING - Default. Compare items as strings
  • SORT_REGULAR - Compare items normally (don't change types)
  • SORT_NUMERIC - Compare items numerically
  • SORT_LOCALE_STRING - Compare items as strings, based on current locale

Technical Details

Return Value: Returns the filtered array
PHP Version: 4.0.1+
PHP Changelog: PHP 7.2: If sorttype is SORT_STRING, this returns a new array and adds the unique elements.
PHP 5.2.9: The default value of sorttype was changed to SORT_REGULAR.
PHP 5.2.1: The default value of sorttype was changed back to SORT_STRING.

❮ PHP Array Reference