JAVA练习题

题目：

有Student学生实体 包含姓名 班级名称 考试成绩 三个属性

向集合中添加五个完整的学生对象（包含所有的属性值）、遍历集合，输出所有的学生信息

package com.qfstu.javase.Week03.Day01;

import java.util.*;
import java.util.function.Consumer;



public class HomeWork01 {
    public static void main(String[] args) {
        //集合只能存放学生对象
        List students = new ArrayList<>();

        //集合中添加元素
        students.add(new Student("张三","2021级云计算三班",100));
        students.add(new Student("李四","2021级云计算三班",97));
        students.add(new Student("王五","2021级云计算三班",85));
        students.add(new Student("马六","2021级云计算三班",68));
        students.add(new Student("田七","2021级云计算三班",95));

        //遍历集合
        //方法一：使用迭代器
        Iterator it = students.iterator();
        while(it.hasNext()) {
            System.out.println(it.next());
        }
        //方法二：使用增强for循环
        System.out.println("---------------------------------------");
        for (Student s: students) {
            System.out.println(s);
        }
        //方法三：使用forEach循环
        System.out.println("---------------------------------------");
        students.forEach(new Consumer() {
            @Override
            public void accept(Student student) {
                System.out.println(student);
            }
        });

        //按照成绩从高到低排序
        //方法一：使用Comparator
        System.out.println("---------------------------------------");
        ((ArrayList) students).sort(new Comparator() {
            @Override
            public int compare(Student o1, Student o2) {
                return o2.getScore() - o1.getScore();
            }
        });
        for (Student s: students) {
            System.out.println(s);
        }
        //方法二：使Student方法实现Iterable接口 并实现排序方法
        System.out.println("---------------------------------------");
        Collections.sort(students);
        for (Student s: students) {
            System.out.println(s);
        }
    }
}

//学生类 包含姓名 班级名称 考试成绩 三个属性
//有无参构造和有参构造 以及Setting and Getting 方法
class Student implements Comparable{
    private String name;
    private String className;
    private int score;

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + ''' +
                ", className='" + className + ''' +
                ", score=" + score +
                '}';
    }

    public Student() {
    }

    public Student(String name, String className, int score) {
        this.name = name;
        this.className = className;
        this.score = score;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getClassName() {
        return className;
    }

    public void setClassName(String className) {
        this.className = className;
    }

    public int getScore() {
        return score;
    }

    public void setScore(int score) {
        this.score = score;
    }

    //按照成绩排序
    @Override
    public int compareTo(Student o) {
        return o.getScore() - this.getScore() ;
    }
}