What does the regex (\d{3})(?=\d) mean?
expression, regex, ruby
Solution
`(?=\d)` is a positive lookahead it means match & capture 3 digits that are followed by a digit.
So something like this will happen:
1234 => capture 123
123a => no match
Problem
I am new to regex, and I am trying to break down the regex so I can understand it better: ``` /(\d{3})(?=\d)/ ``` I understand that `(\d{3})` is capturing 3 digits, but unsure what the second portion is trying to capture. What does `?=` mean?