More efficient way to get all indexes of a character in a string

Question

Instead of looping through each character to see if it\'s the one you want then adding the index your on to a list like so:

     var foundIndexes = new List&         


        

Answer 1

public static String[] Split(this string s,char c = '\t')
    {
        if (s == null) return null;
        var a = new List<int>();
        int i = s.IndexOf(c);
        if (i < 0) return new string[] { s };
        a.Add(i);
        for (i = i+1; i < s.Length; i++) if (s[i] == c) a.Add(i);
        var result = new string[a.Count +1];            
        int startIndex = 0;
        result[0] = s.Remove(a[0]);
        for(i=0;i<a.Count-1;i++)
        {
            result[i + 1] = s.Substring(a[i] + 1, a[i + 1] - a[i] - 1);
        }
        result[a.Count] = s.Substring(a[a.Count - 1] + 1);
        return result;
    }