Java/com/study/demo3/StudentManager.java

package com.study.demo3;
import java.util.*;

public class StudentManager {
    public static void main(String[] args) {
        List<String> studentNames = new ArrayList<>();
        Map<String, Integer> studentScores = new HashMap<>();

        studentNames.add("张三");
        studentNames.add("李四");
        studentNames.add("王五");

        studentScores.put("张三", 85);
        studentScores.put("李四", 77);
        studentScores.put("王五", 99);

        System.out.println("--- 所有学生姓名 ---");
        for (String name : studentNames) {
            System.out.println(name);
        }

        studentScores.put("张三", 70);

        Integer zhangsanScore = studentScores.get("张三");
        System.out.println("\n--- 修改后张三的成绩 ---");
        System.out.println("张三的成绩: " + zhangsanScore);
    }
}