遍历集合

package cn.unuuc.java;
import java.util.ArrayList;
import java.util.function.Consumer;
public class TestLambda {
    public static void main(String[] args) {
        ArrayList<String> list = new ArrayList<>();
        list.add("hello");
        list.add("world");
        list.add("!");
        list.forEach(new Consumer<String>() {
            @Override
            public void accept(String s) {
                System.out.println(s);
            }
        });
        list.forEach(s -> System.out.println(s));
    }
}

在 forEach 方法内，其形参为一个 Consumer 函数接口，所以可以通过Lambda来简化代码

集合排序

    @Test
    public void test08(){
        ArrayList<UserEntity> userEntities = new ArrayList<>();
        userEntities.add(new UserEntity("小明",12));
        userEntities.add(new UserEntity("小红",22));
        userEntities.add(new UserEntity("小蓝",13));
        userEntities.add(new UserEntity("小绿",16));
        userEntities.add(new UserEntity("小紫",21));
        userEntities.sort(new Comparator<UserEntity>() {
            @Override
            public int compare(UserEntity o1, UserEntity o2) {
                return o1.getAge()- o2.getAge();
            }
        });
        userEntities.forEach((u)-> System.out.println(u.toString()));
        // Lambda 实现排序
        userEntities.sort(((o1, o2) -> o1.getAge()-o2.getAge()));
        userEntities.forEach((u)-> System.out.println(u.toString()));
    }

实现线程调用

package cn.unuuc.java;
public class Test {
    public static void main(String[] args) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println(Thread.currentThread().getName());
            }
        }).start();
        // Lambda
        new Thread(()-> System.out.println(Thread.currentThread().getName())).start();
    }
}

应为Runnable 为一个函数接口