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xiexie 发表于 2020-12-7 16:14

PHP之Trait详解

<div>php从以前到现在一直都是单继承的语言,无法同时从两个基类中继承属性和方法,为了解决这个问题,php出了Trait这个特性</div><div>用法:通过在类中使用use 关键字,声明要组合的Trait名称,具体的Trait的声明使用Trait关键词,Trait不能实例化</div><div><br></div><div>如下代码实例:</div><div>&lt;?php</div><div>trait Dog{</div><div>&nbsp; &nbsp; public $name="dog";</div><div>&nbsp; &nbsp; public function bark(){</div><div>&nbsp; &nbsp; &nbsp; &nbsp; echo "This is dog";</div><div>&nbsp; &nbsp; }</div><div>}</div><div>class Animal{</div><div>&nbsp; &nbsp; public function eat(){</div><div>&nbsp; &nbsp; &nbsp; &nbsp; echo "This is animal eat";</div><div>&nbsp; &nbsp; }</div><div>}</div><div>class Cat extends Animal{</div><div>&nbsp; &nbsp; use Dog;</div><div>&nbsp; &nbsp; public function drive(){</div><div>&nbsp; &nbsp; &nbsp; &nbsp; echo "This is cat drive";</div><div>&nbsp; &nbsp; }</div><div>}</div><div>$cat = new Cat();</div><div>$cat-&gt;drive();</div><div>echo "&lt;br/&gt;";</div><div>$cat-&gt;eat();</div><div>echo "&lt;br/&gt;";</div><div>$cat-&gt;bark();</div><div>?&gt;</div><div><br></div>

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