java 给不同成绩分等级

package Studytest;

import java.util.Scanner;

public class Prog5 {
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你的成绩：");
        int fenshu = sc.nextInt();
        grade(fenshu);
    }
   //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);
       }
   }
}