编辑代码

import java.util.*;

public class Prog5 {
    public static void main(String[] args) {
        System.out.println("请输入成绩");
        int n = -1;
        Scanner in=new Scanner(System.in); 
        try {
            //n = Integer.parseInt(args[0]);
            n = in.nextInt();    
            grade(n);
        } catch (ArrayIndexOutOfBoundsException e) {       
            return;
        }
        
        
    }

    //成绩等级计算
    private static void grade(int n) {
        if ((n > 100) || (n < 0)) {
            System.out.println("输入无效");
        }
        else {
            String str = (n >= 90) ? "分，属于A等" : ((n > 60) ? "分，属于B等" : "分，属于C等");

            System.out.println(n + str);
        }
    }
}