Java在子类中调用super()方法

package varycode;
class Grandparent 
{
    public Grandparent()
     {

            System.out.println("GrandParent Created.");
    
    }


    public Grandparent(String string) 
    {

            System.out.println("GrandParent Created.String:" + string);
    
    }

}



class Parent extends Grandparent
{


    public Parent()
     {

            //super("Hello.Grandparent.");

            System.out.println("Parent Created");
    
         // super("Hello.Grandparent.");

      }

}



class Child extends Parent 
{


    public Child()
     {
    
        System.out.println("Child Created");

     }

}



public class TestInherits 
{


    public static void main(String args[])
     {

            Child c = new Child();
    
  }
   
}

结论：在子类中调用super()方法，必须把调用语句放在子类构造的第一句，构造函数是实现初始化功能的，从子类一定要开始向父类实现构造方法。

二、

package varycode;
public class ExplorationJDKSource {

    /**
     * @param args
     */
    public static void main(String[] args) {
        System.out.println(new A());
    }

}

class A{}

 

 默认调用super类的hash值

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