考试成绩大于90为A小于89大于60为B小于60为C

import java.util.Scanner;
public class nesting {

public static void main(String []ages){
    Scanner i=new Scanner(System.in);
    System.out.println("请输入考试成绩");
    int a=i.nextInt();
    char z=a>=90?'A':a<90&&a>60?'B':'C';
    System.out.println("你的成绩为"+z);

}

}