Convert comma separated string of ints to int array

Question

I only found a way to do it the opposite way round: create a comma separated string from an int list or array, but not on how to convert input like string str = "1,2,3,4,5"; to an array or list of ints.

Here is my implementation (inspired by this post by Eric Lippert):

    public static IEnumerable<int> StringToIntList(string str)     {         if (String.IsNullOrEmpty(str))         {             yield break;         }          var chunks = str.Split(',').AsEnumerable();          using (var rator = chunks.GetEnumerator())         {             while (rator.MoveNext())             {                 int i = 0;                  if (Int32.TryParse(rator.Current, out i))                 {                     yield return i;                 }                 else                 {                     continue;                 }             }         }     } 

Do you think this is a good approach or is there a more easy, maybe even built in way?

EDIT: Sorry for any confusion, but the method needs to handle invalid input like "1,2,,,3" or "###, 5," etc. by skipping it.

Answer 1

You should use a foreach loop, like this:

public static IEnumerable<int> StringToIntList(string str) {     if (String.IsNullOrEmpty(str))         yield break;      foreach(var s in str.Split(',')) {         int num;         if (int.TryParse(s, out num))             yield return num;     } } 

Note that like your original post, this will ignore numbers that couldn't be parsed.

If you want to throw an exception if a number couldn't be parsed, you can do it much more simply using LINQ:

return (str ?? "").Split(',').Select<string, int>(int.Parse);