成绩

import java.util.*;

public class Test {

public static void main(String[] args) {
// TODO Auto-generated method stub
try{
Scanner sc=new Scanner(System.in );
System.out.println("输入a:");
int a=sc.nextInt();
if(a<0||a>100){
System.out.println("请重新输入成绩:");
a=sc.nextInt();}
else{
if(a<60)
System.out.println("不及格");
if(a>60&&a<70)
System.out.println("及格");
if(a>70&&a<80)
System.out.println("中");
if(a>80&&a<90)
System.out.println("良");
if(a>90&&a<100)
System.out.println("优");
}
}
catch (InputMismatchException e)
{System.out.println("输入必须为整数");
}

}

}