Question

I found this regular expression in an old system i’m working on.

(\s*)*

I’m pretty sure the extra ” * ” at the end is redundant but I want to make sure is not doing anything before I remove it.
It’s causing a performance issue when it’s used in the regex.matches() method to the point that hangs the entire system if the string used as a parameter has 25+ spaces

Does anybody knows if that particular syntax has a special functionality?

Ps: Its a pretty huge system so I can’t test every posible scenario

Answer 1

Assuming the inner * is greedy, then, yes, I think the outer one is redundant. The outer * attempts to repeat the sub-match, but there would only ever be one instance of the sub-match because it’s greedy.