请教一个关于this的问题
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 ThisDemo07
{
public static void main(String[] args)
{
new A().fun();
}
}
请教下这个结果最后为什么输出helloworld