题解 | 判断学生成绩等级

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String grade =scanner.next();
        if(grade.equals("A")){
            System.out.println("优秀");
        }else if(grade.equals("B")){
            System.out.println("良好");
        }else if(grade.equals("C")){
            System.out.println("及格");
        }else if(grade.equals("D")){
            System.out.println("不及格");
        }else{
            System.out.println("未知等级");
        }

        

    }
}

不能错误的使用==