Question

I need a RegEx for Javascript which will match the string “smith” in lines 1-4 but not in lines 5-8 below.
The numbered lines are fields in an Access database (the fields do not contain the numbers).
What I have so far is:

var xy = 'smith';
MyString = new RegExp('(^|\\W)' + xy + '(\\W|$)', 'i');

This matches the Smiths in lines 1-4, but also those in Lines 7 and 8.
How can I get the expression to also ignore the Smiths which are preceded or followed by a hyphen?

1. Smith, Jones, Wilson
2. Smith Jones Wilson
3. Jones, Smith(Jr), Wilson
4. Jones, Wilson, Smith
5. Arrowsmith, Jones
6. Wilson, Smithson
7. Jones, Smith-Treadstone, Wilson
8. Wilson, Blakely-Smith, Jones

After a week and dozens of attempts, I am asking the experts!

Answer 1

Write the negative character class (\W) yourself and include the hyphen:

MyString = new RegExp('(^|[^a-z0-9_-])' + xy + '([^a-z0-9_-]|$)', 'i');

While \W matches any non-word character (everything but letters, digits and underscores), [^a-z0-9_-] matches any character that is neither such a word character nor a hyphen.

You could of course use \w within that character class:

MyString = new RegExp('(^|[^\\w-])' + xy + '([^\\w-]|$)', 'i');