Regex: Finding strings that doesn't start with X

Question

I am completely hopeless with regular expressions...

I have a Velocimacro named #addButton, and I have a JS function named addButton(). Now I want to find all the places the JS function is called. So I need to search for "addButton", where "addButton" doesn't start with the hash key.

Any ideas?

Answer 1

I don't know what Velocimacro is (judging from the other answer I guess "addButton" will appear on its own line?), but the sure-fire way of finding the word "addButton" that is not preceeded by # is the following:

/(?<!#)\baddButton\b/

It will:

1. (?<!#) (?)
   • Make sure that the current position is not preceeded by a # (hash mark)
2. \b (?)
   • Make sure that the current position is a word boundary (in this case it makes sure that the previous character is not a word character and that the next character is)
3. addButton (?)
   • Match "addButton"
4. \b (?)
   • Make sure that there is a word boundary at the current position. This avoids matching things like "addButtonNew" (because there is no word boundary between "addButton" and "New")

A difference with this regular expression and the other is that this one will not consume the character before "addButton".

A good resource for learning about regular expressions is regular-expressions.info. Click the (?) link in the list above for a link to the relevant page for that part of the regex.

Answer 2

/([^#]|^)addButton/

It will match every string where "addButton" is not preceded by "#" or the beginning of the string.