CODEWITHSUNDEEP
regex
Rhonda
Rhonda

Reputation: 1721

Regex to exclude alpha-numeric characters

I thought [^0-9a-zA-Z]* excludes all alpha-numeric letters, but allows for special characters, spaces, etc.

With the search string [^0-9a-zA-Z]*ELL[^0-9A-Z]* I expect outputs such as

ELL 
ELLs 
The ELL 
Which ELLs

However I also get following outputs

Ellis Island
Bellis

How to correct this?

Upvotes: 1

Views: 477

Answers (2)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626851

You may use

(?:\b|_)ELLs?(?=\b|_)

See the regex demo.

It will find ELL or ELLs if it is surrounded with _ or non-word chars, or at the start/end of the string.

Details:

  • (?:\b|_) - a non-capturing alternation group matching a word boundary position (\b) or (|) a _
  • ELLs? - matches ELL or ELLs since s? matches 1 or 0 s chars
  • (?=\b|_) - a positive lookahead that requires the presence of a word boundary or _ immediately to the right of the current location.

Upvotes: 1

sniperd
sniperd

Reputation: 5274

change the * to +

a * means any amount including none. A + means one or more. What you probably want though is a word boundry:

\bELL\b

A word boundry is a position between \w and \W (non-word char), or at the beginning or end of a string if it begins or ends (respectively) with a word character ([0-9A-Za-z_]). More here about that: What is a word boundary in regexes?

Upvotes: 1

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