【JDK 8-集合框架】5.5 max 和 min 函数

一、max 和 min 函数

二、实战

> 执行结果

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一、max 和 min 函数

• 最大值 和 最小值

二、实战

 

@NoArgsConstructor
@AllArgsConstructor
@Data
public class User {
    private int id;
    private String name;
    private String pwd;
    private int age;

    public User(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public User(int id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }
}

 

import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Optional;

public class Max_MinDemo {
    public static void main(String[] args) {
        List list = Arrays.asList(new User("花无缺", 18), new User("小鱼儿", 18)
                , new User("邀月", 38), new User("怜星", 35));
        Optional optionalUser = list.stream().max((s1, s2) ->
                Integer.compare(s1.getAge(), s2.getAge())
        );
        User user = optionalUser.get();
        System.out.println("最大年龄：" + user);

        optionalUser = list.stream().min((s1, s2) ->
                Integer.compare(s1.getAge(), s2.getAge())
        );
        user = optionalUser.get();
        System.out.println("最小年龄：" + user);

        optionalUser = list.stream().min(Comparator.comparingInt(User::getAge));
        user = optionalUser.get();
        System.out.println("【第二种写法】最小年龄：" + user);
    }

}

> 执行结果