array_unique for arrays inside array

Question

I need a function like array_unique for arrays inside array.

The Case - should be equal, but output "not equal":

<?php
$arr=array(array('a',1),array('a',2));
$arr2=array_unique($arr);
if($arr2==$arr){
  echo "equal";
}
else{
  echo "not equal";
}
?>

How should the code be changed to get output "equal"?

Man, this always comes up. Read the [manual](http://www.php.net/manual/en/function.array-unique.php), it says "Note that array_unique() is not intended to work on multi dimensional arrays." — BoltClock, Mar 06 '11 at 17:00
I don't understand what you mean by "Hi, like array_unique for arrays inside array." — BoltClock, Mar 06 '11 at 17:31

score 53 · Accepted Answer · answered Mar 06 '11 at 17:09

53

You should modify your call for array_unique to have it include the SORT_REGULAR flag.

$arr2 = array_unique($arr, SORT_REGULAR);

answered Mar 06 '11 at 17:09

score 2 · Answer 2 · answered Mar 06 '11 at 17:10

2

If you want to test if the outer array has unique entries, then stringify the inner contents first for a comparison:

$arr1 = array_map("serialize", $arr);
$arr2 = array_unique($arr1);
if ($arr2 == $arr1) {

answered Mar 06 '11 at 17:10

mario

144,265
20
237
291

score -1 · Answer 3 · answered Apr 03 '15 at 19:31

-1

function array_unique_when_values_are_serializable($main_array) {
    return array_map('unserialize', array_values(array_unique(array_map('serialize', $main_array))));
}

answered Apr 03 '15 at 19:31

Hussein Harake

1

1

Please explain your answer. SO exists to teach users, not just answer questions. – Machavity Apr 03 '15 at 20:08

array_unique for arrays inside array

3 Answers3

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