lambda表达式

前提:只能简化函数式接口的匿名内部类（接口只有一个方法）

public static void main(String[] args) {
    Swimming s = new Swimming() {
        @Override
        public void swim() {
            System.out.println("游泳");
        }
    };
}
interface Swimming {
    void swim();
}

lambda

public static void main(String[] args) {
    Swimming s = () -> System.out.println("游泳");
}
interface Swimming {
    void swim();
}