根据另一个数组中的唯一值获取数组？

Question

I have an array of arrays. One of the fields within in the inner array needs to be unique so that when I show the results it only displays unique entries.

array_unique is available but it looks like that only works on single dimension arrays. I could probably do a comparison operation on while iterating through the array but that seems like the least efficient way to do it.

The way the data is stored in the database(not my design) is tricky and I wont be able to just pull in the distinct results using sql.

Any ideas?

Answer 1

You could easily use a combination of array_unique and array_column

$records = array(
    array(
        'id' => 2135,
        'first_name' => 'John',
        'last_name' => 'Doe',
    ),
    array(
        'id' => 3245,
        'first_name' => 'Sally',
        'last_name' => 'Smith',
    )
);

$ids = array_column($records, 'id');
$unique_ids = array_unique($ids);

and then filter in which ever way you see fit

array_filter($records, function($row) use ($unique_ids) {
    return in_array($row['id'], $unique_ids);
} );

EDIT : the filter doesn't actually work now that I think of it, below is a slightly different approach:

array_filter($records, function($row) use ($unique_ids) {
    $array_pos = array_search($row['id'], $unique_ids, true);
    if($array_pos !== false) {
        //need to remove it once used or it wont be unique
        unset($unique_ids[$array_pos]);
    }
    return $array_pos !== false;
} );