Question

我在类似的问题上找了一点，找不到能够帮助我解决问题的答案。

我正在尝试读取用户输入，似乎没有将变量设置为输入。

例如：

 System.out.println("Would you like Syrup?(Y/N)");
   String wantSyrup = keyboard.next();
   char syrupWant = wantSyrup.charAt(0);

   switch (syrupWant){

   case 'y':
       System.out.println("Which syrup would you like?");
        System.out.println("Hot fudge, Chocolate, Caramel, Strawberry");
         syrupChoice = keyboard.nextLine();
        keyboard.nextLine();
        System.out.println("You entered: "+syrupChoice);

        if((syrupChoice.equalsIgnoreCase(hotFudge)) | (syrupChoice.equalsIgnoreCase(chocolateSyrup))|
        (syrupChoice.equalsIgnoreCase(caramel))| (syrupChoice.equalsIgnoreCase(strawberrySyrup))){
        System.out.println(syrupChoice);
        }else{
        System.out.println("Not a valid choice. You now have Hot Fudge as your syrup.");
         syrupChoice = hotFudge;
         }
       break;
   default: break;
   }

这是非常长的If语句搞砸了吗？我从来没有把那么多的OR放在一个如果。

当我输入任何类型的糖浆时，控制台会回来。

Would you like Syrup?(Y/N)
y
Which syrup would you like?
Hot fudge, Chocolate, Caramel, Strawberry
caramel
You entered: 
Not a valid choice. You now have Hot Fudge as your syrup.

注意：它会等到我输入一个值。那就是为什么我有

         syrupChoice = keyboard.nextLine();
    keyboard.nextLine();

但无论我输入什么，它都会出现空白。我显然希望它能正确读取输入并打印正确的值。（如果数据无效，请更改为热门软糖。）

编辑**我现在将代码更改为：

 System.out.println("Would you like Syrup?(Y/N)");
   String wantSyrup = keyboard.next();
   char syrupWant = wantSyrup.charAt(0);

   switch (syrupWant){

   case 'y':
       System.out.println("Which syrup would you like?");
        System.out.println("Hot fudge, Chocolate, Caramel, Strawberry");
         syrupChoice = keyboard.nextLine();
        keyboard.nextLine();
        System.out.println("You entered: "+syrupChoice);

      if(syrupChoice.equalsIgnoreCase(hotFudge)
              || syrupChoice.equalsIgnoreCase(chocolateSyrup)
              || syrupChoice.equalsIgnoreCase(caramel)
              || syrupChoice.equalsIgnoreCase(strawberrySyrup))
                {
                    System.out.println(syrupChoice);
                }else{
                    System.out.println("Not a valid choice. You now have Hot Fudge as your syrup.");
                    syrupChoice = hotFudge;
                }
                break;
    default: break;
        }

结果仍然相同

Answer 1

有一些小问题。首先，|是按位或运算符，||是逻辑或运算符。你也有一些无关的keyboard.nextLine()。

System.out.println("Would you like Syrup?(Y/N)");
String wantSyrup = keyboard.nextLine();
char syrupWant = wantSyrup.charAt(0);

switch (syrupWant){
    case 'y':
        System.out.println("Which syrup would you like?");
        System.out.print("Hot fudge, Chocolate, Caramel, Strawberry: ");
        syrupChoice = keyboard.nextLine();
        System.out.print("You entered: ");

        if(syrupChoice.equalsIgnoreCase(hotFudge)
            || syrupChoice.equalsIgnoreCase(chocolateSyrup)
            || syrupChoice.equalsIgnoreCase(caramel)
            || syrupChoice.equalsIgnoreCase(strawberrySyrup))
        {
            System.out.println(syrupChoice);
        }else{
            System.out.println("Not a valid choice. You now have Hot Fudge as your syrup.");
            syrupChoice = hotFudge;
        }
        break;
    default: break;
}

Answer 2

用if语句中的逻辑OR：|替换二进制OR：||：

if((syrupChoice.equalsIgnoreCase (hotFudge)) || (syrupChoice.equalsIgnoreCase (chocolateSyrup)) || (syrupChoice.equalsIgnoreCase (caramel)) || (syrupChoice.equalsIgnoreCase (strawberrySyrup))){ System.out.println(syrupChoice); }

程序无法正确读取输入

2 个答案: