在课外如何使用$ this？ [英] How to use $this in outside of class?

问题描述

我们可以在课外使用 $ this 吗？请看下面的例子，

Can we use $this outside of class. Please look at the example below,

<?php 

class Animal {

    public function whichClass() {
        echo "I am an Animal!";
    }

    public function sayClassName() {
        $this->whichClass();
    }
}

class Tiger extends Animal {

    public function whichClass() {
        echo "I am a Tiger!";
    }

    public function anotherClass() {
        echo "I am a another Tiger!";
    }

}

$tigerObj = new Tiger();

//Tiger::whichClass();

$this->anotherClass();

在这里我创建了新对象 $ tigerObj = new Tiger（）; 之后，我尝试使用 $ this ，但是它抛出错误。那么可以在课外使用 $ this 吗？如果否，则
$ this 引用当前对象。那么，为什么不使用它呢？

Here I have created new object $tigerObj = new Tiger(); after that I tried to use $this but it throwing error. So is that possible to use $this from outside of the class ? If no, $this refers to the current object. So why don't we use this ?

推荐答案

不可能以这种方式使用$ this，您可以创建对象该类，然后扩展您要调用的方法。见下文...

Its not possible to use $this in this way, you can create object of that class and then extend the methods which you would like to call. See below ...

class Animal {

    public function whichClass() {
        echo "I am an Animal!";
    }

    public function sayClassName() {
        $this->whichClass();
    }
}

class Tiger extends Animal {

    public function whichClass() {
        echo "I am a Tiger!";
    }

    public function anotherClass() {
        echo "I am a another Tiger!";
    }

}

$tigerObj = new Tiger();

echo $tigerObj->anotherClass();

您将得到结果我是另一只老虎！

You will get result "I am a another Tiger!"

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