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);
  }
}