An Extension to Get All the Digits of a Number

Introduction

In this tip, I will show one method of returning all the digits of an integer in an array.

Using the Code

public static class Extensions
{
    static int[] Digits(this int value)
    {
        // get the sign of the value
        int sign = Math.Sign(value);

        // make the value positive
        value *= sign;

        // get the number of digits in the value
        int count = (int)Math.Truncate(Math.Log10(value)) + 1;

        // reserve enough capacity for the digits
        int[] list = new int[count];

        for (int i = count - 1; i >= 0; --i)
        {
            // truncate to get the next value
            int nextValue = value / 10;

            // fill the list in reverse with the current digit on the end
            list[i] = value - nextValue * 10;

            value = nextValue;
        }

        // make the first digit the correct sign
        list[0] *= sign;

        return list;
    }
}

Points of Interest

Note that the first array position preserves the sign of the number.

History

• 9 March 2017: First version