Java 基础一些代码练习笔记（继承+接口+多态）

public class Test3{public static void main(String[] args){MyClass myClass = new MyClass();myClass.output();myClass.output2();myClass.output3();}}interface MyInterface{public void output();}interface MyInterface2{public void output2();}class MyParent{public void output3(){System.out.println("output3");}}class MyClass extends MyParent implements MyInterface, MyInterface2{public void output(){System.out.println("output");}public void output2(){System.out.println("output2");}}

public class Test4{public static void main(String[] args){/*BB bb = new BB();AA aa = bb;bb.output();*/AA aa = new BB();BB bb = (BB)aa;bb.output();}}interface AA{public void output();}class BB implements AA{public void output(){System.out.println("BB");}}