The Factory mode, singleton mode and registration mode of PHP design mode

The three most common design patterns for all object-oriented objects are: Factory mode, Singleton mode, registration (device) mode

Factory mode, factory method or class to produce objects, hundred not directly in the code new

Singleton mode, which allows an object of a class to create only one

Registration mode, global sharing and exchanging objects

Factory mode factory.php

<?phpclass database{public    function __construct ()    {        return ' database\n ';    }  } Factory class factory{public    static function CreateDatabase ()    {        $db = new Database ();        return $db;    }} $db = Factory::createdatabase (); $db 1 = factory::createdatabase (); $db 2 = Factory::createdatabase (); Var_dump ($db, $db 1, $db 2), #object (database) #1 (0) {#} #object (database) #2 (0) {#} #object (database) #3 (0) {#}

Single case Mode singleton.php

<?php//single case mode class database{    protected static $db;    The construction method is private and prevents the outer layer from being directly new    private function __construct () {        //code    }     static function getinstance () {        if (Self:: $db) {            return self:: $db;        } else{self            :: $db = new self ();            Return self:: $db;}}    } $db = Database::getinstance (); $db 1 = database::getinstance (); $db 2 = Database::getinstance (); Var_dump ($db, $db 1, $db 2), #object (database) #1 (0) {#} #object (database) #1 (0) {#} #object (database) #1 (0) {#}

Factory mode and single case combined use

<?phpclass database{    protected static $db;    Private Function __construct () {            }     static function getinstance () {        if (self:: $db) {            return self:: $db;        } else{self            :: $db = new self ();            Return self:: $db;}}    } Class factory{public    static function CreateDatabase () {        return database::getinstance ();    }} var_dump ( Factory::createdatabase ());

Registrar class register.php

<?php//registrar mode class register{    protected static $objects;     static function set ($alias, $object) {self        :: $objects [$alias] = $object;    }    static function Get ($name) {        return self:: $objects [$name];    }    function _unset ($alias) {        unset (self:: $objects [$alias]);}    } Register::set (' db1 ', $db); Register::get (' db1 ');