Question

Given searchString = "23423asdfa-''"

This regular expression should evaluate to false but it does not! Any ideas?

Regex rgx = new Regex(@"[\w-]*");
rgx.IsMatch(searchString)

Answer 1

It’s because you haven’t constrained it to match the entire string. Hence it is allowed to consider matches on subsets of the string. A very large subset of the string matches the data hence the regex returns true.

Try the following to force it to match the entire input.

Regex rgx = new Regex(@"^[\w-]*$");
rgx.IsMatch(searchString)