php验证身份证号码

    public function checkIdCard($idcard_num='')
    {
        $idcard_len = strlen($idcard_num);
        if($idcard_num == '' || !in_array($idcard_len,array(15,18)) ){
            return false;
        }
        if($idcard_len === 15){
            if(!preg_match("/^[1-9]\d{7}((0\d)|(1[0-2]))(([0|1|2]\d)|3[0-1])\d{3}$/", $idcard_num)){
                return false;
            }
        }
        if($idcard_len === 18){
            if(!preg_match("/^[1-9]\d{5}[1-9]\d{3}((0\d)|(1[0-2]))(([0|1|2]\d)|3[0-1])\d{3}(\d|x|X)$/", $idcard_num)){
                return false;
            }
        }
        return true;
    }