ARRAY_UNIQUE(3) 1 ARRAY_UNIQUE(3)
array_unique - Removes duplicate values from an array
SYNOPSIS
array array_unique (array $array, [int $sort_flags = SORT_STRING])
DESCRIPTION
Takes an input $array and returns a new array without duplicate values.
Note that keys are preserved. array_unique(3) sorts the values treated as string at first, then will keep the first key encountered for
every value, and ignore all following keys. It does not mean that the key of the first related value from the unsorted $array will be kept.
Note
Two elements are considered equal if and only if (string) $elem1 === (string) $elem2 i.e. when the string representation is the
same, the first element will be used.
PARAMETERS
o $array
- The input array.
o $sort_flags
- The optional second parameter $sort_flags may be used to modify the sorting behavior using these values: Sorting type flags:
o SORT_REGULAR - compare items normally (don't change types)
o SORT_NUMERIC - compare items numerically
o SORT_STRING - compare items as strings
o SORT_LOCALE_STRING - compare items as strings, based on the current locale.
RETURN VALUES
Returns the filtered array.
CHANGELOG
+--------+---------------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------------------------+
|5.2.10 | |
| | |
| | Changed the default value of $sort_flags back to |
| | SORT_STRING. |
| | |
| 5.2.9 | |
| | |
| | Added the optional $sort_flags defaulting to |
| | SORT_REGULAR. Prior to 5.2.9, this function used |
| | to sort the array with SORT_STRING internally. |
| | |
+--------+---------------------------------------------------+
EXAMPLES
Example #1
array_unique(3) example
<?php
$input = array("a" => "green", "red", "b" => "green", "blue", "red");
$result = array_unique($input);
print_r($result);
?>
The above example will output:
Array
(
[a] => green
[0] => red
[1] => blue
)
Example #2
array_unique(3) and types
<?php
$input = array(4, "4", "3", 4, 3, "3");
$result = array_unique($input);
var_dump($result);
?>
The above example will output:
array(2) {
[0] => int(4)
[2] => string(1) "3"
}
SEE ALSO
array_count_values(3).
NOTES
Note
Note that array_unique(3) is not intended to work on multi dimensional arrays.
PHP Documentation Group ARRAY_UNIQUE(3)