Java新手错误:找不到符号

时间:2015-03-04 09:27:11

标签: java switch-statement

我想让这个人输入例如112进入控制台,按回车键,然后结束" Hello,Mars。"作为答案。

我被困在"错误:找不到符号"。

import java.util.Scanner;

public class Main {
    public static void main(String[] args)
    {
        int n1 = userVar;

        switch ( userVar )
        {
            case 111:
                System.out.println("Hello, Earth.");
                break;
            case 112:
                System.out.println("Hello, Mars.");
                break;
            case 113:
                System.out.println("Hello, Jupiter.");
                break;
            default:
                System.out.println("Hello, Space.");
        }

        Scanner keyboard = new Scanner(System.in);
        n1 = keyboard.nextInt();
    }
}

现在,我尝试将int更改为

int userVar;

        Scanner keyboard = new Scanner(System.in);
        userVar = keyboard.nextInt();

但最终还是遇到了错误:变量userVar可能尚未初始化"。请注意,我在Ideone上执行此操作。

2 个答案:

答案 0 :(得分:4)

首先,给userVar一个默认值:

int userVar = 0;

然后尝试为其分配用户输入:

Scanner keyboard = new Scanner(System.in);
userVar = keyboard.nextInt();

答案 1 :(得分:0)

public class main(){
    public static void main(String []args){
       int userVar = 0;
       System.out.print("ENTER NO > ");
       Scanner keyboard = new Scanner(System.in);
       userVar = keyboard.nextInt(); //The given input stoted in userVar.
      // Now Apply Switch-case :)

} }