通过php用三种简单的方法实现手机号中间四位(n位)用星号显示:
$mobile = '13912345678';
//1.字符串截取法
$newMobile1 = substr($mobile, 0, 5).'****'.substr($mobile, 9);
echo $newMobile1.'<br/>';
//2.替换字符串的子串
$newMobile2 = substr_replace($mobile, '****', 5, 4);
echo $newMobile2.'<br/>';
//3.用正则
$newMobile3 = preg_replace('/(\d{5})\d{4}(\d{2})/', '$1****$2', $mobile);
echo $newMobile3;