Interface with inherited class jobs

Hands-on brain: Run the testinherits.java example, observe the output, and note the call relationship that summarizes the constructor method between the parent class and the child class modifies The code of the parent constructor method, explicitly calling Grandparent Another constructor, note whether the calling code is the first sentence, which affects significant .

Source:

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 ();

}

}

Run :

After modifying the code of the Parent constructor method, explicitly call Another constructor of grandparent.

Operation Result:

Summary : The construction method of a subclass must call the parent class's constructor before it is run. calling the base class construction method through super must be the first statement in the subclass construction method.

2. write your own code to test the following features: In subclasses, to invoke the overridden method in the parent class, you can use the super keyword.

source code ;

Write code Test Properties : in subclasses, to invoke methods overridden in a parent class, you can use the super keyword.

Fanyalei 2015.11.09

Class father{// parent

public void Show () {

System.out.println ("The parent class method is called .");

}

}

Class Son extends father{// Subclass

public void Show () {

Super. Show ();

System.out.println (" subclass method called .");

}

}

Class Override {

public static void Main (string[] args) {

Son a=new son ();

A.show ();

}

}

Run:

Interface with inherited class jobs