Question

I have a bidimensional array in php like this:

Array (
        [0] => Array
            (
                        [index1] => -1
                        [index2] => 77
                        [description] => 7
                    )
        [1] => Array
            (
                        [index1] => -1
                        [index2] => 77
                        [description] => 5
                    )
        [2] => Array
            (
                        [index1] => -1
                        [index2] => 78
                        [description] => 12
                    )
)

I need to find if there is a duplicate between the first level arrays.
But only considering the keys index1 and index2.

In the example above, it should return true because 0 and 1 have the same index1 and index2.

Answer 1

function hasDupes($array, $delim = '|') {
    $values = array();
    foreach ($array as $v) {
        $v = $v['index1'] . $delim . $v['index2'];
        if (isset($values[$v])) {
            return true;
        }
        $values[$v] = 0;
    }
    return false;
}

No need for nested loops or complete walks (or even multiple walks) over the array, which btw is what most of the suggested array_something functions do internally. Iterate once and stop when you see an element that you’ve seen before.