通过while循环进行数组验证

Question

我正在做“石头、纸、剪刀”游戏，我想检查输入是否与任何数组匹配，现在我有这个代码并且它运行完美：

String[] rockArray = {"Rock","rock","1"},
         paperArray = {"Paper","paper","2"},
         scissorsArray = {"Scissors","scissors","3"};
String[][] answersArray = {rockArray, paperArray, scissorsArray};

//Scanner
Scanner scan = new Scanner(System.in);

// Input
System.out.print("\nRock, Paper or Scissors? -> ");
String answer = scan.next();

 // Checking if the input contains the right values
 while(!Arrays.asList(answerRock).contains(answer) &&
       !Arrays.asList(answerPaper).contains(answer) &&
       !Arrays.asList(answerScissors).contains(answer)) {

         System.out.print("Try again: ");
         answer = scan.next();
 }

但我想让它变得简单，这是我的想法，但由于某种原因它不起作用：

// Here is my arrays 
String[] rockArray = {"Rock","rock","1"},
         paperArray = {"Paper","paper","2"},
         scissorsArray = {"Scissors","scissors","3"};
String[][] globalArray = {rockArray, paperArray, scissorsArray};

// Input
System.out.print("\nRock, Paper or Scissors? -> ");
String answer = scan.next();

//Validation
while(!Arrays.asList(globalArray).contains(answer) {
      System.out.println("Try again: ");
      answer = scan.next();
}

非常感谢！

Answer 1

String[][] globalArray = {rockArray, paperArray, scissorsArray};
...
Arrays.asList(globalArray)

对Arrays.asList() 的调用将创建包含 3 个元素的列表，即 3 数组，而不是包含数组内容的列表。然后，当您使用contains 搜索元素时，您将始终得到false，因为answer 永远不会出现在数组中（怎么会，它是String 而不是数组）。

我建议你这样做：

List<String> allAnswers = Arrays.asList(rockArray);
allAnswers.addAll(Arrays.asList(paperArray));
allAnswers.addAll(Arrays.asList(scissorsArray));
...
while(!allAnswers.contains(answer)) {
  ...

这也使您不必一遍又一遍地调用Arrays.asList()，从而提高性能。

Answer 2

!Arrays.asList(globalArray).contains(answer) 不起作用，因为Arrays.asList(...) 方法将输出List<String[]> 而不是List<String>。

如果你真的想使用asList(...)，你必须输入String[] allPossibleInputString

Answer 3

你的第二个代码 sn-p 不起作用，因为你不能这样做!Arrays.asList(globalArray).contains(answer)。

一种解决方案是将三个数组的内容复制到您的全局数组中，如下所示：

String[] rockArray = {"Rock","rock","1"},
         paperArray = {"Paper","paper","2"},
         scissorsArray = {"Scissors","scissors","3"};
String[] globalArray = new String[9];
/* Copy Contents To Global Array */
System.arraycopy(rockArray, 0, globalArray, 0, 3);
System.arraycopy(paperArray, 0, globalArray, 3, 3);
System.arraycopy(scissorsArray, 0, globalArray, 6, 3);

现在你可以这样做了：

while(!Arrays.asList(globalArray).contains(answer)) {
    System.out.println("Try again: ");
    answer = scan.nextLine();
}