内部类2

package oop.Demon10;

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

    UserService userService = new UserService() {
        public void hello(){
            
        }

    };
}

}
class Apple{
public void eat(){
System.out.println("1");
}
}

interface UserService{
void hello();

}