PHP如何实现JS中escape和unescape方法

?PHP?,????urlencode()?urldecode()????????JS??escape()?unescape()???

1. urlencode()??????????URL??,???????????????ASCII??,??????%???????:

$str = "Hello ??!";
$encoded_str = urlencode($str);
echo $encoded_str; // ??:Hello 世界!

2. urldecode()???????????URL??????????,??????ASCII???????????????:

$encoded_str = "Hello 世界!";
$decoded_str = urldecode($encoded_str);
echo $decoded_str; // ??:Hello ??!

??????,urlencode()?urldecode()????????????????,???????????????????????????,????htmlspecialchars()???

??,???????URL???????URL?????,????urlencode()???????????HTML???????HTML????,????htmlspecialchars()???