java - 程序无法正确读取输入

Question

我查找了一些类似的问题，但找不到一个答案足以帮助我解决问题的问题。

我正在尝试读取用户输入，但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;
   } 

是不是那个非常长的 If 语句把事情弄乱了？我从来没有在一个 if 中放入那么多 OR。

当我输入任何类型的糖浆时，控制台都会返回此信息..

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:它会等待我输入一个值。这就是为什么我有

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

但无论我输入什么，它都会显示空白。我显然希望它正确读取输入并打印正确的值。 (如果数据无效，请更改为热软糖。)

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;
        }

结果还是一样

Answer 1

有一些小问题。首先，|是按位或运算符，||是逻辑或运算符。此外，您还有一些无关的 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;
}