note 80009 deleted from ref.array by felipe

Note Submitter: php atdomain yereth incountry nl 

----

I was looking for a array transpose but surprisingly it's not in PHP.

Here's my humble version:

<?php
    function array_transpose($array, $selectKey = false) {
        if (!is_array($array)) return false;
        $return = array();
        foreach($array as $key => $value) {
            if (!is_array($value)) return $array;
            if ($selectKey) {
                if (isset($value[$selectKey])) $return[] = $value[$selectKey];
            } else {
                foreach ($value as $key2 => $value2) {
                    $return[$key2][$key] = $value2;
                }
            }
        }
        return $return;
    }
?>

As you can see, it does a bit more. You can submit a Key name, which should be selected from the transposed array, if you only want that specific key.

Examples:
<?php
    $people = array(
        array('id' => 1, 'name' => 'john', 'occupation' => 'unemployed'),
        array('id' => 5, 'name' => 'pete', 'occupation' => 'dentist'),
        array('id' => 19, 'name' => 'hank', 'occupation' => 'software developer')
    );

    print_r(array_transpose($people));
    print_r(array_transpose($people, 'name'));
?>

Will output:

Array(
    [id] => Array(
            [0] => 1
            [1] => 5
            [2] => 19
    )
    [name] => Array (
            [0] => john
            [1] => pete
            [2] => hank
    )
    [occupation] => Array (
            [0] => unemployed
            [1] => dentist
            [2] => software developer
    )
)

Array (
    [0] => john
    [1] => pete
    [2] => hank
)

I use it all the time, especially for structured array data such as this.