Extract substring from a string using regex in javascript

Question

I am new to javascript, How to extract substring that matches a regex in a string in javascript?

For example in python:

version_regex =  re.compile(r'(\d+)\.(\d+)\.(\d+)')
line = "[2021-05-29] Version 2.24.9"
found = version_regex.search(line)
if found:
  found.group() // It will give the substring that macth with regex in this case 2.24.9

I tried these in javascript:

let re = new RegExp('^(\d+)\.(\d+)\.(\d+)$');
let x = line.match(re);

but I am not getting the version here.

Thanks in advance.

Don't use new RegExp if you're not constructing the regexp dynamically. Use a RegExp literal. — Barmar
– Barmar, Commented Aug 22, 2021 at 6:06
The reason it's not working is because you need to escape the backslashes in the string. You wouldn't have that problem if you used a literal. — Barmar
– Barmar, Commented Aug 22, 2021 at 6:07

Guerric P · Accepted Answer · 2021-08-22 06:09:48Z

10

You can use RegExp.prototype.exec which returns an Array with the full match and the capturing groups matches:

const input = '[2021-05-29] Version 2.24.9';

const regex = /(\d+)\.(\d+)\.(\d+)/;

let x = regex.exec(input);

console.log(x);

answered Aug 22, 2021 at 6:09

Guerric P

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