Question

import java.io.*;

public class Color {
    public void main() throws IOException {
        BufferedReader br;
        br = new BufferedReader(new InputStreamReader(System.in));

        System.out.println("Enter your choice");
        System.out.println("Enter V for Violet");
        System.out.println("Enter I for Indigo");
        System.out.println("Enter B for Blue");
        System.out.println("Enter G for Green");
        System.out.println("Enter Y for Yellow");
        System.out.println("Enter O for Orange");
        System.out.println("Enter R for Red");
        char choice;
        choice = (char) br.read();
        switch (choice) {
        case V:
            System.out.println("The spectrum color is Violet");
            break;
        case I:
            System.out.println("The spectrum color is Indigo");
            break;
        case B:
            System.out.println("The spectrum color is Blue");
            break;
        case G:
            System.out.println("The spectrum color is Green");
            break;
        case Y:
            System.out.println("The spectrum color is Yellow");
            break;
        case O:
            System.out.println("The spectrum color is Orange");
            break;
        case R:
            System.out.println("The spectrum color is Red");
            break;
        default:
            System.out.println("Wrong Input");
        }
    }
}

它说----＆gt; cannot find symbol - variable v ...当我试图用bluej编码时。我目前正在学习java编程，这是我的第一个基本java程序。

Answer 1

你应该尝试将你的字母写成真正的字符：

case 'V':

        System.out.println("The spectrum color is Violet");

        break;

您现在正在做的是检查选项是否是变量V，当然，它不存在。

Answer 2

要在Java中使用字符文字，您需要使用单引号。此外，您可能希望接受大写和小写 v 。所以你可以这样做：

switch (Character.toUpperCase(choice))
{
   case 'V':

等等

Answer 3

你应该比较字符。试试case 'V'。

Answer 4

检查区分大小写。＆＃39; V＆＃39; ＆＃39; V＆＃39; ...

说＆＃34;找不到符号 - 变量V＆＃34;

4 个答案: