PHP实现手机号码中间四位用星号（*）隐藏的自定义函数分享

Method 1：
function hidtel($phone){
    $IsWhat = preg_match(/(0[0-9]{2,3}[\-]?[2-9][0-9]{6,7}[\-]?[0-9]?)/i,$phone); //固定电话
    if($IsWhat == 1){
        return preg_replace(/(0[0-9]{2,3}[\-]?[2-9])[0-9]{3,4}([0-9]{3}[\-]?[0-9]?)/i,$1****$2,$phone);
    }else{
        return  preg_replace(/(1[358]{1}[0-9])[0-9]{4}([0-9]{4})/i,$1****$2,$phone);
    }
}

Method 2：
$num = "13966778888"
$str = substr_replace($num,****,3,4);

$phonenum = "13966778888";
echo hidtel($phonenum);