Trim a String, or an Array of Strings Recursively

// Usage: trim_r( array(' 123 ', '   abc') );

// Trim a string or an array of strings recursively
function trim_r($array) {
    if (is_string($array)) {
        return trim($array);
    } else if (!is_array($array)) {
        return '';
    }
    $keys = array_keys($array);
    for ($i=0; $i