Regex replace for multiple matches

Question

Trying to figure out a Regex to inject and remove a string (in this case var.par_) at the following locations:

Very Beginning
After ^
After ^OR

Example input string when injecting:

job=developer^language=js^ORlanguage=react^ORlanguageSTARTSWITHjava

Should result in output of

var.par_job=developer^var.par_language=js^ORvar.par_language=react^ORvar.par_languageSTARTSWITHjava

and vice versa when removing:

var.par_language=react^ORvar.par_languageSTARTSWITHjava

should result in

language=react^ORlanguageSTARTSWITHjava

My current feeble attempt was this:

var input = "job=developer^language=js^ORlanguage=react^ORlanguageSTARTSWITHjava";


const replaceToken = "var.par_";


var output = input.replace(/^()?/, replaceToken).replace(/\^()?/g, '^' + replaceToken);

You can match those locations with `(^|\^OR|\^)` – Barmar Sep 02 '20 at 21:57 — Barmar, Sep 02 '20 at 21:57
Added my current attempt barman – Seth Duncan Sep 02 '20 at 22:27 — Seth Duncan, Sep 02 '20 at 22:27
What's the point of the empty group `()?` – Barmar Sep 02 '20 at 22:29 — Barmar, Sep 02 '20 at 22:29

score 1 · Accepted Answer · answered Sep 02 '20 at 22:35

1

let input = "job=developer^language=js^ORlanguage=react^ORlanguageSTARTSWITHjava";
const replaceToken = "var.par_";
let output = input.replace(/^|\^OR|\^/g, '$&' + replaceToken);
console.log(output)

The regexp /^|\^OR|\^/ matches each of your locations. $& in the replacement gets replaced with the match. So there's no need to use multiple calls to .replace().

answered Sep 02 '20 at 22:35

Barmar

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Honestly I thought I tried that combo with the pipe and was getting no luck. Maybe it was an errant typo, but thank you. Also I called you the incorrect name, so I apologize. – Seth Duncan Sep 02 '20 at 22:38
You're not the first. But there's automatic name completion after `@`, you should use that. – Barmar Sep 02 '20 at 22:40

Regex replace for multiple matches

1 Answers1