关于后端:创建型设计模式原型-Prototype

简介

原型模式反对依照一个对象为模板，创立出另一个截然不同的对象。

简略说就是把 A 对象的属性，都赋值到 B 上，留神必须是深拷贝，即 clone 后的 AB 关联的对象是不同的对象。

角色

• 形象原型类

  定义 clone 办法

• 具体实现类

  实现 clone 办法

类图

代码

class Prototype{    public $primitive;    public $component;    public $circularReference;    public function __clone()    {        $this->component = clone $this->component;        $this->circularReference = clone $this->circularReference;        $this->circularReference->prototype = $this;    }}class ComponentWithBackReference{    public $prototype;    public function __construct(Prototype $prototype)    {        $this->prototype = $prototype;    }}function clientCode(){    $p1 = new Prototype();    $p1->primitive = 245;    $p1->component = new \DateTime();    $p1->circularReference = new ComponentWithBackReference($p1);    $p2 = clone $p1;    if ($p1->primitive === $p2->primitive) {        echo "Primitive field values have been carried over to a clone. Yay!\n";    } else {        echo "Primitive field values have not been copied. Booo!\n";    }    if ($p1->component === $p2->component) {        echo "Simple component has not been cloned. Booo!\n";    } else {        echo "Simple component has been cloned. Yay!\n";    }    if ($p1->circularReference === $p2->circularReference) {        echo "Component with back reference has not been cloned. Booo!\n";    } else {        echo "Component with back reference has been cloned. Yay!\n";    }    if ($p1->circularReference->prototype === $p2->circularReference->prototype) {        echo "Component with back reference is linked to original object. Booo!\n";    } else {        echo "Component with back reference is linked to the clone. Yay!\n";    }}clientCode();

output:

Primitive field values have been carried over to a clone. Yay!Simple component has been cloned. Yay!Component with back reference has been cloned. Yay!Component with back reference is linked to the clone. Yay!