lambda表达式简单使用

package com.example.demo.lambda;

import java.util.ArrayList;
import java.util.List;

public class test  {
     
    public static void main(String[] args) {
     
        //介绍：目的是在使用但接口（只含有一个方法的几口）匿名类时，让代码更加简洁
        //lambada表达式通常就是一个匿名方法（函数）
        //1.原始
        StudentService studentService= new StudentService() {
     
            @Override
            public String work() {
     
                return "222";
            }
        };
        System.out.println(studentService.work());
        //2.简化后，就是将类名方法名都去掉，然后加上一个->符号
        StudentService studentService2 = ()-> "2333";
        System.out.println(studentService2.work());


        //==========================================================
        //1.原始
        TargetThread targetThread = new TargetThread();
        Thread thread = new Thread(targetThread);
        thread.start();
        //2.第一步简化
        Thread thread1 = new Thread(new Runnable() {
     
            @Override
            public void run() {
     
                System.out.println("ok1");
            }
        });
        thread1.start();
        //3.再一步简化
        Thread thread2 = new Thread(() -> {
     
            System.out.println("ok2");
        }
        );
        thread2.start();

        //=================================

        List<Integer> s = new ArrayList<>();
        s.add(11);
        s.add(13);
        s.add(9);
        s.sort((Integer o1, Integer o2) ->{
     
             return o1 - o2;
        });
        System.out.println(s);

    }


}
interface StudentService {
     
    String work();
}
class TargetThread implements Runnable{
     
    @Override
    public void run() {
     
        System.out.println("ok");
    }
}