Question

Suppose I have a string like this:

w="abc#name,xy.abc=abc"

I want to replace the first and the third "abc" with another string. I used this code:

puts w.gsub(/\babc\b/,"replacer");
# => replacer#name,xy.replacer=replacer

where the second "abc" is replaced, which was not what I expected. Then I changed to the following pattern:

puts w.gsub(/[^\.]\babc\b/,"replacer");
# => abc#name,xy.abcreplacer

where the first "abc" is not replaced. I have no idea now how to fix it.

Answer 1

You can try

/\b(?<!\.)abc\b/

but it’s a rather brute-force solution with negative look-behind.