面向对象的第一次pta作业第三题：电话键盘字母数字转换

import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        Scanner letter = new Scanner(System.in);
        String str;
        str=letter.nextLine();
        String str1=str.toUpperCase();
        char s=str1.charAt(0);
        
        if(s>'Z'||s<'A') {
            System.out.print(str.charAt(0));
            System.out.print(" is an invalid input");
        }
        else if(s<='C')
            System.out.print(2);
        else if(s<='F')
            System.out.print(3);
        else if(s<='I')
            System.out.print(4);
        else if(s<='L')
            System.out.print(5);
        else if(s<='O')
            System.out.print(6);
        else if(s<='S')
            System.out.print(7);
        else if(s<='V')
            System.out.print(8);
        else
            System.out.print(9);
            

    }

}

 

 

还是有一种在复习c语言的感觉呢~