Question

I need help understanding how to write a for loop that takes in a certain amount of integers (must be 1 through 10) and it stops taking in numbers once 0 is entered (0 will be the last number). My code so far is:

   import java.util.Scanner;
   public class countNum {

      public static void main(String[] args) {

        int[] array;

        Scanner input = new Scanner(System.in);
        System.out.println ("Enter in numbers (1-10) enter 0 when finished:");

        int x = input.nextInt();

        while (x != 0) {
          if (x > 2 && x < 10) {
          //Don't know what to put here to make array[] take in the values
          }
          else
          //Can I just put break? How do I get it to go back to the top of the while loop?
        }
      }   

     }

}

I don’t understand how to simultaneously initialize an array with a set length while having the Scanner read a certain amount of digits of that unknown length, until 0 is entered, and then the loop stops taking in input for the array.

Thanks for any help!

Answer 1

Ok here’s the bit more detail: –

• You need to use an ArrayList if you want a dynamically increasing array. You do it like this: –

  List<Integer> numbers = new ArrayList<Integer>();
  

• Now, in your above code, you can put your number reading statement (nextInt) inside the while loop, since you want to read it regularly. And put a condition in while loop to check whether the entered number is an int or not: –

  int num = 0;
  while (scanner.hasNextInt()) {
      num = scanner.nextInt();
  }
  

• Further, you can move on your own. Just check whether the number is 0 or not. If it is not 0, then add it to ArrayList: –

  numbers.add(num);
  

• If its 0, break out of your while loop.

• And you don’t need that x != 0 condition in your while loop, as you are already checking it inside the loop.