Question

I need to remove leading zeroes from the numerical part of an expression (using .net 2.0 C# Regex class).

Ex:

PAR0000034 -> PAR34

WP0003204 -> WP3204

I tried the following:

//keep starting characters, get rid of leading zeroes, keep remaining digits
string result = Regex.Replace(inputStr, "^(.+)(0+)(/d*)", "$1$3", RegexOptions.IgnoreCase)

Obviously, it did not work. I need a bit of help to find the mistake.

Answer 1

You don’t need a regular expression for that, the Split method can do that for you.

Splitting on '0', removing empty entries (i.e. between the mulitple zeroes), and limiting the result to two strings will give you the two strings before and after the leading zeroes. Then you just put those two strings together again:

string result = String.Concat(
  input.Split(new char[] { '0' }, 2, StringSplitOptions.RemoveEmptyEntries)
);