What is super () in Java

To say super is to say this first.


2. Can be used inside a non-static member of a class to represent the current object. At this point, this is a final normal variable, which has a static type, which is the class C itself; it has a dynamic type, which is the type of the current object. You can call member functions on it, pass it to other functions, and so on. As long as a final variable of type C can appear, it can appear.


1. Represents the constructor that invokes the parent class. is also a special syntax, not a variable, no type.


However, note that this super.method () is just as long as Some_var.method (), a syntactic sugar. In essence, "Super" is not a variable at all.


So, if super is a variable that also points to the current object, then whatever the static type of super is, Super.method () is bound to call the version of the subclass, not what we expected, but statically select the version of the parent class.

So, you just have to think of super.xxx as a special grammar, such as "super::xxx".

Since super is not a variable, it's not as "= =" as a normal variable, or it seems normal to pass it to a function, right? Besides, you don't really need it, you can do it with this.

3. Another function of super is to call the parent class's protected function. Only through the magic of "super" can we manipulate the protected members of the parent class, and there is no other way.

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What is super () in Java