PHP str_replace

Question

I have the string $var in which I need to replace some text. The first \"X\" needs to be replaced by \"A\", the second \"X\" needs to be replaced by B and so on, here is an exam

Answer 1

Lets give it a shot, too, just for the heck of it ;)

$input = "X X X X";

function replace($input, array $replacements)
{
    $replacer = function(array &$i, array &$r, &$o) use(&$replacer) {
        if (count($i) === 0 || count($r) === 0) return;

        $i_cur = array_shift($i);

        if (ctype_space($i_cur)) $o .= $i_cur;
        else $o .= array_shift($r);

        $replacer($i, $r, $o);
    };

    $replacer(str_split($input), $replacements, $output);

    return $output;
}

var_dump(replace($input, range('A', 'Z')));