Java super（）继承 [英] Java super() inheritance

问题描述

问题的简短摘要：我有一个由子类扩展的父类。

A short summary of the question: I have a parent class which is extended by a child class.

     public class Parent{

        public Parent(){
          //constructor logic
        }
     }

这个子类使用super调用Parent的构造函数：

This child class calls the Parent's constructor using super:

     public class Child extends Parent{

         public Child(){
            super();
         }
     }

我想知道我是否要扩展Child类如果我可以在Grandchild类的构造函数中调用super（）方法：

I was wondering if I were to extend the Child class if I could call the super() method in the Grandchild class' constructor:

    public class Grandchild extends Child{

         public Grandchild(){
            super();
         }
    }

推荐答案

super （）在继承上调用构造函数一级，如果有一个无参数构造函数，则隐式调用它。

super() is calling constructor one level up on the inheritance and it is called implicitly, if there is a no-arg constructor.

从最高级别的继承初始化对象，在您的情况下，它是对象>父>子>孙。

Objects are initialized from the top level of inheritance, in your case it is Object > Parent > Child > Grandchild.

来自文档：

If a constructor does not explicitly invoke a superclass constructor, the Java compiler
automatically inserts a call to the no-argument constructor of the superclass. If the super 
class does not have a no-argument constructor, you will get a compile-time error. Object does 
have such a constructor, so if Object is the only superclass, there is no problem. 

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