Javascript ignore regex if at the end

Question

I'm trying to format some strings with delimiters using regex, and its almost done, but my delimiter continues to appear at end of string.

For example, I have this code:

var myString = "abcdefghi"
var result = myString.replace(/(.{1,3})(?:(?=.{3})\.(.{1,3})(?:(?=.{3}))?)?/g, '$1.');
console.log(result) // abc.def.ghi.

And I am expecting abc.def.ghi

You can also try [`s.replace(/.{3}\B/g, '$&.')`](https://tio.run/##y0osSyxOLsosKNEts/j/Pye1RKFYwVZBKTEpOSU1LT0jU8maCyRYlAoSLtYrSi3ISUxO1dDXqzaujXHST9dRUFdR01PXtOZKzs8rzs9J1cvJT9cAKtf8/x8A). This works with `\B` which represents a [*non word boundary*](https://stackoverflow.com/questions/4541573/what-are-non-word-boundary-in-regex-b-compared-to-word-boundary) ([regex101 demo](https://regex101.com/r/CIgj6m/1)). — bobble bubble, Aug 06 '23 at 20:00

score 1 · Accepted Answer · answered Aug 06 '23 at 18:04

1

You could use this approach

var myString = "abcdefghi";
var result = myString.match(/.{1,3}/g).join(".");
console.log(result)

answered Aug 06 '23 at 18:04

Peterrabbit

1 Answers1