How to match a specific word without spaces and without an additional letter in the starting or ending?

Question

Let's say I have word phone

It's possible matches in my case are as follows

phone (no space in the beginning and in the ending just phone)
"phone" (can have special characters at the end or in the beginning)

Cases to be Neglected [Here I'll mark the space with \s]

phone\s (any space in either in the beginning or in the end should not be matched)
phoneno (any alphabets or numbers appended with phone should not be matched)

I've tried the following regex [^\w\s]items[^\w\s] link

But It didn't match the case of phone with no space in the beginning and the end as it requires 1 letter other than space and alphabets in the beginning and the end

Kindly suggest any other solutions which satisfies above mentioned cases

You can find the regex here

I already have solution for that case. I need regex for matching the word phone when it don't have any space around it and reject the word phone when it have space. Could you please help? — Magaesh, Jun 11 '19 at 15:09
Sorry, Above Regex doesn't satisfy all the cases mentioned in my question. Thanks for your time though. — Magaesh, Jun 12 '19 at 05:54
Sorry, but what you ask is what you get. `(?<!\S)...(?!\S)` does exactly that: **with no space in the beginning and the end** — Wiktor Stribiżew, Jun 12 '19 at 06:56
Finally, Thanks It works fine for all the cases, Kindly suggest your fav site to learn regex. — Magaesh, Jun 12 '19 at 07:50
I do not know your level of regex knowledge :) so, I can only suggest doing all lessons at [regexone.com](http://regexone.com/), reading through [regular-expressions.info](http://www.regular-expressions.info), [regex SO tag description](http://stackoverflow.com/tags/regex/info) (with many other links to great online resources), and the community SO post called [What does the regex mean](http://stackoverflow.com/questions/22937618/reference-what-does-this-regex-mean). Also, [rexegg.com](http://rexegg.com) is worth having a look at. — Wiktor Stribiżew, Jun 12 '19 at 08:00

score 1 · Accepted Answer · answered Jun 12 '19 at 07:59

You may use custom word boundaries, a combination of \b and (?<!\S) / (?!\S):

(?<![\w\s])phone(?![\w\s])

See the regex demo and the regex graph:

The (?<![\w\s]) negative lookbehind pattern matches a location in string that is NOT immediately preceded with a word or whitespace char.

The (?![\w\s]) negative lookahead pattern matches a location in string that is NOT immediately preceded with a word or whitespace char.

How to match a specific word without spaces and without an additional letter in the starting or ending?

1 Answers1