php方法在没有初始化对象的情况下访问意外错误

Question

I am trying to create a user class in php but I have a problem in accessing the method before create the object with and without static

<?php

class user{

    private $firstName;
    private $lastName;
    private $email;
    private $password;

    public function __construct($firstName,$lastName,$email,$password)
    {
        $this->$firstName=$firstName;
        $this->$lastName=$lastName;
        $this->$email=$email;
        $this->$password=$password;
        echo "create user";
    }

    public static function login($email,$password)
    {
        echo "login";
        if ( ! isset(self::$_instance)) {
            self::$_instance = new self();
        }

        $this->$email=$email;
        $this->$password=$password;

       /*
        login data
       */

        return self::$_instance;
    }
}

$mz= new user("mz","z","a@z.v","zxfef");
$mm= new user::login("mz","vc");
?>

for the last line I got an error:

Parse error: syntax error, unexpected 'login' (T_STRING), expecting variable (T_VARIABLE) or '$'

Answer 1

login() is a static method, so you need to access it directly on the class using the Scope Resolution Operator( :: ). You can't use new in connection to static methods. new is only for instantiating objects of this class.

$mm = user::login("mz","vc"); // remove new