How can I get the substring using regular expressions?

August 4, 2022

I have a string like so:

https://test/api/files/123/versions/1/watermark_content=123456

And I would like to separate this into:

https://test/api/files/123/versions/1/

and

watermark_content=123456

How can I achieve this using regular expressions? Or is there an even better/simpler way to do this without regular expressions?

>Solution :

This splits the two parts:

const href = 'https://test/api/files/123/versions/1/watermark_content=123456';

const matches = href.match(/^((?![/]watermark_content=.*).*[/])(watermark_content=[^/]*)/);

console.log(matches[1]);
console.log(matches[2]);

I’m assuming the "right side" (matches[2]) should be a path node that starts with "watermark_content=".

^((?![/]watermark_content=.*).*[/]) matches everything that doesn’t have "watermark_content=…". And should end with a "/".

(watermark_content=[^/]*) matches "watermark_content=" and everything next to it until a "/" (excluding it, and that doesn’t mean "/" should exist).