Creating unique arrays

Question

I have a multidimensional array such as

Array
(
    [0] => Array
        (
            [id] => 1355698
            [comment] => hello
        )

    [1] => Array
        (
            [id] => 1355699
            [comment] => hey
        )

    [2] => Array
        (
            [id] => 1355700
            [comment] => hello
        )

)

The id will always be unique, so the uniqueness of the element will be based on the subarray's value of comment. In this case, array[0] has a duplicate array[2]. (I wonder if there is a better way to phrase this explaination).

array_unique() will not work in this case. Is there an alternative? Thanks!

I believe this will answer your question: http://stackoverflow.com/questions/2442230/php-getting-unique-values-of-a-multidimensional-array — Mark1inLA, May 24 '12 at 02:51
Follow Mark1inLA's answer and it leads to http://stackoverflow.com/questions/1861682/php-multi-dimensional-array-remove-duplicate - the accepted answer on that question should do exactly as you ask. — Robbie, May 24 '12 at 03:28
The accepted answer from http://stackoverflow.com/questions/1861682/php-multi-dimensional-array-remove-duplicate would use the comment as the array key. I don't think its a good solution for the problem, since a comment might have hundreds of characters. — flowfree, May 24 '12 at 05:26

score 2 · Accepted Answer · answered May 24 '12 at 02:41

2

Create a new array with id and comment as key=>value pairs, then array_unique().

answered May 24 '12 at 02:41

flowfree

16,356
12
52
76

like: `array( 1344698 => "hello", 1355699, => "hey", 1355700 => "hello");` – Joe Flynn May 24 '12 at 02:44
If you wind up with this solution, you'll also have a convenient way to access the comments without iterating. – Chris Henry May 24 '12 at 02:56

score 0 · Answer 2 · answered May 24 '12 at 02:55

0

$uniqueArray = array();
foreach ($nonUniqueArray as $i) {
    $uniqueArray[$i['comment']] = $i;
}

// optionally:
// $uniqueArray = array_values($uniqueArray);

var_dump($uniqueArray);

answered May 24 '12 at 02:55

deceze

510,633
85
743
889

Creating unique arrays

2 Answers2