Possible Duplicate:
php multi-dimensional array remove duplicate
I have an array like this:
$a = array (
0 => array ( 'value' => 'America', ),
1 => array ( 'value' => 'England', ),
2 => array ( 'value' => 'Australia', ),
3 => array ( 'value' => 'America', ),
4 => array ( 'value' => 'England', ),
5 => array ( 'value' => 'Canada', ),
)
How can I remove the duplicate values so that I get this:
$a = array (
0 => array ( 'value' => 'America', ),
1 => array ( 'value' => 'England', ),
2 => array ( 'value' => 'Australia', ),
4 => array ( 'value' => 'Canada', ),
)
I tried using array_unique, but that doesn’t work due to this array being multidimensional, I think.
Edit: I also need this array to be multi-dimensional and in this format, I can’t flatten it.
array_unique is using string conversion before comparing the values to find the unique values:
Note: Two elements are considered equal if and only if
(string) $elem1 === (string) $elem2. In words: when the string representation is the same. The first element will be used.
But an array will always convert to Array:
var_dump("Array" === (string) array());
You can solve this by specifying the SORT_REGULAR mode in the second parameter of array_unique:
$unique = array_unique($a, SORT_REGULAR);
Or, if that doesn’t work, by serializing the arrays before and unserializing it after calling array_unique to find the unique values:
$unique = array_map('unserialize', array_unique(array_map('serialize', $a)));
Answer：
Here 🙂
<?php
$a = array (
0 => array ( 'value' => 'America', ),
1 => array ( 'value' => 'England', ),
2 => array ( 'value' => 'Australia', ),
3 => array ( 'value' => 'America', ),
4 => array ( 'value' => 'England', ),
5 => array ( 'value' => 'Canada', ),
);
$tmp = array ();
foreach ($a as $row)
if (!in_array($row,$tmp)) array_push($tmp,$row);
print_r ($tmp);
?>
Answer：
Use SORT_REGULAR flag.
$unique_array = array_unique($a, SORT_REGULAR);
I’m not sure why it helps but it does. At least with php 5.3
Tags: phpphp
