array_map and append string to elements of an array

Question

I have an array like this:

$a = array('aa', 'bb', 'cc', 'dd');

I want to add the 'rq' string at the beginning of all the elements of the array. Is it possible to do it by calling array_map() on this array?

Answer 1

$a = array_map(function ($str) { return "rq$str"; }, $a);

Answer 2

You can have it like this:

<?php
    $a = array('aa', 'bb', 'cc', 'dd');
    $i=0;
    foreach($a as $d) {
        $a[$i] = 'rq'.$d;
        $i++;
    }
    var_dump($a);
?>

Answer 3

function addRq($sValue) {
    return 'rq'.$sValue;
}
$newA = array_map("addRq", $a);

Also see this example.