Java 扫描仪，Arraylist 和 while 循环

Question

I am trying a to get user input and add the value in Arraylist as long it is positive number. If user enters a negative number the program should stop. This is my code it take up to three numbers then stops. Thank you in advance.

class ProjectOne{

public void counterLoop() {
    Scanner userNumber = new Scanner(System.in);
    ArrayList<Integer> number = new ArrayList();

    System.out.println("Enter Your No: ");
    number.add(userNumber.nextInt());

    while (true){
        System.out.println("Enter a number: ");
        number.add(userNumber.nextInt());
        System.out.println(number);

        if (userNumber.nextInt() >= 0){
            break;
        }
    }
}

}

Answer 1

public void counterLoop() {
    Scanner userNumber = new Scanner(System.in);
    ArrayList<Integer> number = new ArrayList<>();
    while (true) {
        System.out.println("Enter a number: ");
        int n = userNumber.nextInt();
        if(n >= 0)
            number.add(n);
        else break;
    }
}

You should add the number to the list iff it is >= 0. If a negative number is input, the loop should break. You can print your list to see the result,

for(int i : number)
   System.out.print(i + " ");