package 第十一次; class A{ private B b = null ; public void fun() { this.b = new B(this); this.b.fun() ; } public void print() { System.out.println("Hello World!!!"); } }; class B{ private A a = null; public B(A a) { this.a = a; } public void fun() { this.a.print(); } }; public class Shyi { public static void main(String[] args) { // TODO Auto-generated method stub new A().fun(); } }
public abstract class A { private String name; public A(String name) { this.name=name; } public String getName() { return this.name; } public abstract void fun(); }
public class B extends A { //抽象类不能实例化 public B(String name) { super(name); } public void fun() { System.out.println(super.getName()); } }
public class DemoAB { public static void main(String[] args) { B b =new B("悟空"); b.fun(); } }