了解内部类

(Outer类)
package oop.demo10;

public class Outer {
private int id;
public void out(){
System.out.println(“这是外部类的方法”);
}
public class Inner{
public void in(){
System.out.println(“这是内部类的方法”);
}
}
}

(main方法)
package oop;

import oop.demo10.Outer;

public class Application {
public static void main(String[] args) {
Outer outer = new Outer();
//通过外部类来实例化内部类
Outer.Inner inner = outer.new Inner();
inner.in();
}
}

(特殊)
package oop.demo10;

public class Test {
public static void main(String[] args) {
//没有名字初始化类，不用将实例保存到变量中
new Apple().eat();
}
}

class Apple{
public void eat(){}
}