CODEWITHSUNDEEP
javascriptregexregex-lookarounds
David Müller
David Müller

Reputation: 5351

Javascript RegEx and escaping advice needed

I want to replace one or more question marks with a replacement (template language), like that:

var translation = "this is a ???";
console.log(translation.replace(/(\?+)/g, "replacement")); //this is a replacement

But now, I recently ran into an issue where the question mark was actually intended as a question and should not be escaped. I decided to go for the ~ as escaping character, so this should not be escaped:

var translation = "this should not be escaped, cause it's a question, is it~?";
console.log(translation.replace(/[^~](\?+)/g, "replacement"));

Works so far. However, if I go with multiple question marks (requirement for the template syntax), I end up with crap:

var translation = "this should not be escaped, cause it's a question, is it~???";
console.log(translation.replace(/[^~](\?+)/g, "replacement")); 
//this should not be escaped, cause it's a question, is it~replacement  <-- ???

Any suggestion on how to do that? A classical \ as escaping character would make me happier than the ~ but I ran into issues with that as well.

Upvotes: 0

Views: 52

Answers (2)

Barmar
Barmar

Reputation: 782673

Use negative lookbehind:

translation.replace(/(<!~)\?+/g, "replacement");

Upvotes: 1

Explosion Pills
Explosion Pills

Reputation: 191819

~ should probably be used to escape only a single character (which I think would be expected). Users of the template could write ~?~?~? to escape multiple characters.

As for the replacement, [^~] still selects a character.

translation.replace(/([^~])\?+/g", "$1replacement")

The $1 will insert the selected character back again

Upvotes: 1

Related Questions