CODEWITHSUNDEEP
c#.netregex
jwaliszko
jwaliszko

Reputation: 17064

Collection regex filtering issue

I have such expression;

collection = collection.Where(x => Regex.IsMatch(x, "[a-zA-Z0-9+#-\\.\\s]+", RegexOptions.IgnoreCase)).ToList();

before filtering, collection have such elements:

a+1, a#1, a-1, a.1, a 1, ab, a'1, a@1, a*1, a&1, a:1, a!1

after, I want only following elements to stay:

a+1, a#1, a-1, a.1, a 1, ab

but no element is thrown away.

I need to preserve only elements which consist of: letters, numbers, plus, hash, minus, dot, whitespaces.

How to correct this regex expression ?

Upvotes: 2

Views: 117

Answers (1)

Heinzi
Heinzi

Reputation: 172230

Your regex checks if the element contains a substring matching the text. Since all of your elements contain a (which matches the regular expression), all elements are preserved.

If you want the substring to match exactly, enclose your regular expression in ^...$ (marking the beginning and the end of the text):

... Regex.IsMatch(x, "^[a-zA-Z0-9+#-\\.\\s]+$", ...

EDIT: In addition, you need to move the dash - to the end of the group:

... Regex.IsMatch(x, "^[a-zA-Z0-9+#\\.\\s-]+$", ...

Otherwise, #-\\. matches all characters from # to ..

Upvotes: 3

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