Follow

Keep Up to Date with the Most Important News

By pressing the Subscribe button, you confirm that you have read and are agreeing to our Privacy Policy and Terms of Use
Contact

Why does this regex execution not return the match

My regex is:

let a = new RegExp("(?:https?:)?\/\/(?:www\.)?(?:facebook|fb)\.com\/(?<profile>(?![A-z]+\.php)(?!marketplace|gaming|watch|me|messages|help|search|groups)[\w.\-]+)\/?", "g")

It’s basically a modification of the one seen here for facebook to extract the username from a facebook url.

My test string is https://facebook.com/peterparker and my code is:

MEDevel.com: Open-source for Healthcare and Education

Collecting and validating open-source software for healthcare, education, enterprise, development, medical imaging, medical records, and digital pathology.

Visit Medevel

a.exec("https://facebook.com/peterparker")

When I try this in RegExr, it works fine. It shows the correct group captured (peterparker).

regexr behaviour

Yet, when I try the same code in Google Chrome’s console, the code returns null:

google chrome console

Why doesn’t it show up in the chrome console?

>Solution :

Since you’re creating your regex from a string, you have to escape your backslashes.

let a = new RegExp("(?:https?:)?\/\/(?:www\.)?(?:facebook|fb)\\.com\/(?<profile>(?![A-z]+\\.php)(?!marketplace|gaming|watch|me|messages|help|search|groups)[\\w.\\-]+)\\/?", "g")
console.log(a.exec("https://facebook.com/peterparker"))

Creating it inline does not have this problem.

let a = /(?:https?:)?\/\/(?:www\.)?(?:facebook|fb)\.com\/(?<profile>(?![A-z]+\.php)(?!marketplace|gaming|watch|me|messages|help|search|groups)[\w.\-]+)\/?/g
console.log(a.exec("https://facebook.com/peterparker"))
Add a comment

Leave a Reply

Keep Up to Date with the Most Important News

By pressing the Subscribe button, you confirm that you have read and are agreeing to our Privacy Policy and Terms of Use

Discover more from Dev solutions

Subscribe now to keep reading and get access to the full archive.

Continue reading