java - How to sort Integer digits in ascending order without Strings or Arrays?

Question

I'm trying to sort the digits of an integer of any length in ascending order without using Strings, arrays or recursion.

Example:

Input: 451467
Output: 144567

I have already figured out how to get each digit of the integer with modulus division:

int number = 4214;

while (number > 0) {
    IO.println(number % 10);
    number = number / 10;
}

but I don't know how to order the digits without an array.

Don't worry about the IO class; it's a custom class our professor gave us.

Answer 1

It's 4 lines, based on a for loop variant of your while loop with a little java 8 spice:

int number = 4214;

List<Integer> numbers = new LinkedList<>(); // a LinkedList is not backed by an array
for (int i = number; i > 0; i /= 10)
    numbers.add(i % 10);
numbers.stream().sorted().forEach(System.out::println); // or for you forEach(IO::println)