Use RegEx to split a string in Javascript (preserving separators) | Notes
Kumar Abhishek
Posted on February 2, 2021
Use the Javascript split() function with a Positive Lookbehind Regular Expression
to split a string while preserving the separators in the sub-strings:
split(/(?<=[<separator characters go here>])/)
What is Lookbehind? §
Lookbehind in regular-expression allows to match a pattern only when it follows the given lookbehind pattern (without actually matching it).
Syntax §
- Positive lookbehind:
(?<=Y)X
matches X if there is Y before it. - Negative lookbehind:
(?<!Y)X
matches X if there is no Y before it.
One limitation is that Javascript only supports fixed length lookbehind patterns. So, you cannot use it to split by a separator pattern with variable length.
Demo §
💖 💪 🙅 🚩
Kumar Abhishek
Posted on February 2, 2021
Join Our Newsletter. No Spam, Only the good stuff.
Sign up to receive the latest update from our blog.