如何以最简单的方式解释'this'关键字？

Question

I am using 'this' keyword for a long time. But when someone asks me to explain it, I am confused that how to explain it. I know that I can use this in a method of class to access any variable and method of the same class.

    class MyClass{

      function MyMethod1(){
        echo "Hello World";
      }

      function MyMethod2(){
        $this->MyMethod1();
      }

    }

Is it a object of a class that we don't need to initialise and can be used only within the class or anything else. How to explain?

Thanks

Answer 1

A class is a mold for an object: it specifies how the object looks like (variables) and what it can do (functions).

If you instanciate a class: you create an object. If you create the class, you can use "this" to refer to the object itsself. This is why you can't set the "this", because it's related to the object. It's a special, read-only variable.