URL-Safe String base64 encoding and decoding

If you use the Base64_encode and Base64_decode methods directly, the resulting string may not be applicable to the URL address. The following methods can be used to resolve the problem:
URL-safe string encoding:

function Urlsafe_b64encode ($string) {$data = Base64_encode ($string);   $data = str_replace (Array (' + ', '/', ' = '), array ('-', ' _ ', '), $data); return $data;}

URL-safe String decoding:

function Urlsafe_b64decode ($string) {$data = Str_replace (Array ('-', ' _ '), Array (' + ', '/'), $string);   $mod 4 = strlen ($data)% 4;   if ($mod 4) {$data. = substr (' = = = ', $mod 4); } return Base64_decode ($data);}

URL-Safe String base64 encoding and decoding