1 package day1_28;
2
3 import java.util.Scanner;
4 import java.util.Vector;
5
6 /**
7 * Vector 向量集合类
8 * 添加元素 addElement（Object obj）
9 * 读取元素 Object elementAt(int index)
10 */
11
12 public class ScoreTest {
13 public static void main(String[] args) {
14 ScoreTest st = new ScoreTest();
15 st.score();
16 }
17
18 //不提示输入学生人数，按任意负数表示结束成绩输入
19 public void score() {
20
21 Scanner sc = new Scanner(System.in);
22 Vector v = new Vector();
23 int score;
24 int maxScore = 0;
25 for (; ; ) {
26 System.out.print("请输入学生成绩(负数表示输入结束)：");
27 score = sc.nextInt();
28 if (score < 0) {
29 break;
30 }
31 if (score > 100) {
32 System.out.println("输入的数据非法，请重新输入");
33 continue;
34 }
35 v.addElement(score);//自动装箱
36 System.out.println();
37 if (maxScore < score) {
38 maxScore = score;
39 }
40 }
41
42 System.out.println("最高分是：" + maxScore);
43
44 char level;
45 for (int i = 0; i < v.size(); i++) {
46 Object obj = v.elementAt(i);
47 score = (int)obj;//向下转型为Integer,然后自动拆箱
48 if (maxScore - score <= 10) {
49 level = 'A';
50 } else if (maxScore - score <= 20) {
51 level = 'B';
52 } else if (maxScore - score <= 30) {
53 level = 'C';
54 } else {
55 level = 'D';
56 }
57 System.out.println("学生" + (i + 1) + "的成绩是:" + score
58 + " 等级是" + level);
59 }
60
61 }
62 }
