Question

I’m trying to use InStr to find the first character that isn’t a “0” (starting from the left-hand side) in strings like this:

000000000001
000000004092
000000000052
000000001006

Can this be done with InStr, or should I use something different?

Answer 1

If you are looking for an index of an item that is not zero (that may also be a non-digit) use this regular expression: [^0]

Dim pos as Integer = Regex.Match(str, "[^0]").Index

Keep in mind, Regex functions require the following library call:

Imports System.Text.RegularExpressions

This will not work well when the string is composed entirely of zeros, so you may want to modify the expression to allow zero to be the last (or the only) character in the string:

`([^0])|(0$)`
          ^--- This meta-character matches an end-of-string marker