How to convert int to List

Question

I want an solution to convert an input int say 010 to list of int {0,1,0}. Below is code I tried, works until 0 is encountered.

Int num = 010;
List<int> listOfInt = new List<int>();
While(num > 0)
listOfInt.Add(num%10);
num / = 10;

I just want to split entered int and convert it to list of int. LINQ is fine if that could be efficient!

Answer 1

As others already mentioned 010 is identical to 10 when having parsed as int. However you could have your number as string coming from a console-input for example.

string myNumber = "010";

This can be split on every character quite easy using LINQ:

var intList = myNumber.Select(x => Convert.ToInt32(x.ToString())).ToList();

As every character is internally an int where '0' equals 49 you have to convert every single character to a string before which is done by using ToString.

Answer 2

Console.WriteLine("Enter a number:")
var input = Console.ReadLine();

List<int> result = input.Select(c => int.Parse(c.ToString())).ToList();

Answer 3

There is no difference between 010 and 10 either in computer arithmetic or real life. Zero is zero.

If you want to convert the number to a specific string format and extract the characters, perform the same steps as the statement:

10.ToString("000").Select(c=>c-48).ToList();

The result is a list with the numbers 0,1,0.

The expression c-48 takes advantage of the fact that characters are essentially ints, and digits start from 0 upwards. So 48 is 0, 1 is 49 etc.

If the input is a string, eg "10" you'll have to pad it with 0s up to the desired length:

"10".PadLeft(3,'0').Select(c=>c-48).ToList()

The result will be 0,1,0 again.

If, after all, you only want to retrieve characters from a paddes string, you only need padding, as a String is an IEnumerable. You can copy the characters to an array with String.ToCharArray() or to a List as before:

"10".PadLeft(3,'0').ToList()

Answer 4

string num = "010";
List<int> listOfInt = new List<int>();
foreach(char item in num)
{
  listOfInt.Add(Convert.ToInt32(item.ToString()));
}