دستور کار PHP array_unique()

توابع آرایه PHP

مثال

حذف مقادیر تکراری از آرایه:

<?php
$a=array("a"=>"red","b"=>"green","c"=>"red");
print_r(array_unique($a));
?>

Run Instance

Definition and Usage

The array_unique() function removes duplicate values from the array and returns the resulting array.

When several array elements have equal values, 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 maintain the key name type of the first array item.

Syntax

array_unique(array)
Parameters Description
array Required. Specifies the array.
sortingtype

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

  • SORT_STRING - Default. Compares items as strings.
  • SORT_REGULAR - Arranges each item in regular order (Standard ASCII, without changing the type).
  • SORT_NUMERIC - Treats each item as a number.
  • SORT_LOCALE_STRING - Treats each item as a string, based on the current locale setting (which can be changed by setlocale()).

Description

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

Technical Details

Return Value: Returns the filtered array.
PHP Version: 4.0.1+
Update Log:

In PHP 5.2.10,sortingtype The default value is changed back to SORT_STRING.

In PHP 5.2.9,sortingtype The default value is changed to SORT_REGULAR. In previous versions, the default value of sortingtype was SORT_STRING.

توابع آرایه PHP