1.推導lambda   先從外部類->靜態內部類->區域性內部類->匿名內部類->lambda表示式 

/*
 推導lambda表示式
 */
public class TestLambda {

    //3.內部類
    static class Like2 implements Ilike{

        @Override
        public void lambda() {
            System.out.println("i like lambda2");
        }
    }

    public static void
 
 main(String[] args) {
        Ilike like = new Like();
        like.lambda();

        like =new Like2();
        like.lambda();

        //4.區域性內部類
        class Like3 implements Ilike{
            @Override
            public void lambda() {
                System.out.println("i like lambda3");
            }
        }

        like 
 
= new Like3();
        like.lambda();

        //5.匿名內部類,沒有類的名稱，必須藉助介面或者父類
        like = new Ilike(){
            @Override
            public void lambda() {
                System.out.println("i like lambda4");
            }
        };
        like.lambda();

        //6.lambda表示式簡化
        like =()->{
            System.out.println(
 
"i like lambda5");
        };
        like.lambda();
    }
}

//1.定義一個函式式介面：介面中只有一個方法
interface  Ilike{
    void lambda();
}

//2.實現類
class Like implements Ilike{

    @Override
    public void lambda() {
        System.out.println("i like lambda");
    }
}