Java 练习(输入学生成绩，判断成绩等级)

效果如下：

import java.util.Scanner;

public class ArrayDemo1 {
	public static void main(String[] args) {
		//1.使用Scanner 读取学生个数
		Scanner scanner = new Scanner(System.in);
		System.out.println("请输入学生人数: ");
		int number = scanner.nextInt();
		
		//2.创建数组，存储学生成绩，动态初始化
		int[] scores = new int[number];
		
		//3.给数组中的元素赋值
		int maxScore = 0;
		System.out.println("请输入"+ number + "个学生成绩: ");
		for(int i = 0; i< scores.length; i++) {
			scores[i] = scanner.nextInt();
			
			//4.获取数组中的元素的最大值：最高分
			if(maxScore < scores[i]) {
				maxScore = scores[i];
			}
		}
		
		//5.根据每个学生成绩与最高分的差值，得到每个学生的等级，并输出等级和成绩
		char level;
		for(int i = 0; i< scores.length; i++) {
			if(maxScore - scores[i] <= 10) {
				level = 'A';
			}else if(maxScore - scores[i] <= 20) {
				level = 'B';
			}else if(maxScore - scores[i] <= 30) {
				level = 'C';
			}else {
				level = 'D';
			}
		
		System.out.println("Student "+ i + " score is " + scores[i] + ", grade is " + level);
		}
	}

}