在控制台中输入多个数字

Question

所以我有以下chuckj代码和我想要它做的是用户在netbeans控制台中输入5个数字。我想这样做的方式是他可以输入一些通过分配数字与空格或逐行显示如下

但我想要的是“输入一串数字”只有在需要时才可见，例如当他需要输入下一个数字时。有可能这样做吗？

以下代码

完成以下操作

Scanner reader = new Scanner(System.in);
        int number;
        List<Integer> numbers = new ArrayList<>();
        for (int i = 0; i < 5; i++) {
            System.out.println("Enter a string of numbers");
            number = reader.nextInt();
            numbers.add(number);
        }

        System.out.println("size" + numbers.size());
        for(int takenNumber : numbers){
            System.out.println(takenNumber);
        }

Answer 1

你可以这样做：

Scanner reader = new Scanner(System.in);
List<Integer> numbers = new ArrayList<>();

int numbersEntered = 0; // Stores how many numbers the user has entered so far
while (numbersEntered < 5) { // Keep asking if they have not entered 5 numbers yet
    System.out.println("Enter a string of numbers");
    String[] input = reader.nextLine().split(" "); // Split the input by spaces into an array
    numbersEntered += input.length; // Add the number of numbers they entered to the variable
    for (int i = 0; i < input.length; i++) {
        if (numbers.size() < 5) { // Only add the numbers if the list is not full
             numbers.add(Integer.parseInt(input[i])); // Add each number they entered to the numbers list
        }
    }
}

Answer 2

您可以使用hasNext() Scanner函数在没有其他提示的情况下继续阅读。尝试：

Scanner reader = new Scanner(System.in);
int number;
ArrayList<Integer> numbers = new ArrayList<Integer>();
int i = 0;
while((i < 5))
{
  System.out.println("Enter a string of numbers:");
  if(reader.hasNextLine())
  {
    String[] numbersRead = reader.nextLine().split("\\s");
    System.out.print("Read:");
    for(int n = 0; n < numbersRead.length; n++)
    {
      numbers.add(Integer.parseInt(numbersRead[n]));
      i++;
    }
    System.out.println();
  }
}