php隱藏手機號中間4位方法

$tel = '13838389438';
//1.字符串截取法
$new_tel1 = substr($tel, 0, 3).'****'.substr($tel, 7);
var_dump($new_tel1);
//2.替換字符串的子串
$new_tel2 = substr_replace($tel, '****', 3, 4);
var_dump($new_tel2);
//3.用正則
$new_tel3 = preg_replace('/(\d{3})\d{4}(\d{4})/', '$1****$2', $tel);