Get Index of First non-Whitespace Character in C# String

Question

Is there a means to get the index of the first non-whitespace character in a string (or more generally, the index of the first character matching a condition) in C# without

Answer 1

var match = Regex.Match(" \t test  ", @"\S"); // \S means all characters that are not whitespace
if (match.Success)
{
    int index = match.Index;
    //do something with index
}
else
{
    //there were no non-whitespace characters, handle appropriately
}

If you'll be doing this often, for performance reasons you should cache the compiled Regex for this pattern, e.g.:

static readonly Regex nonWhitespace = new Regex(@"\S");

Then use it like:

nonWhitespace.Match(" \t test  ");