Using RegExp and match in JS getting back more than one match, but only want one

Question

I have a string of 'image/png', the 'png' could also be 'jpg' 'gif' 'jpeg'. I have a new RegExp(/^image[/](jpe?g|gif|png)$/) which seems to work for the most part.

I use the .match() method and it returns an array like so ['image/png', 'png']. I want it to return an array with ['image/png']. I looked up some other post and saw the recommended ^$ for beginning and end and even tried the \b which is I think some type of word bound special character.

None of these are returning only the one match, which is what I want.

Expressions that should work:

'image/png' should return from match ['image/png'] not ['image/png', 'png']
'image/jpg' should return from match ['image/jpg'] not ['image/jpg', 'jpg']
'image/jpeg' should return from match ['image/jpeg'] not ['image/jpeg', 'jpeg']
'image/gif' should return from match ['image/gif'] not ['image/gif', 'gif']

Use `/^image[/](?:jpe?g|gif|png)$/`. The point is that you need to replace the capturing group with a non-capturing one. — Wiktor Stribiżew, Oct 18 '17 at 16:43
Maybe not quite a duplicate, but coming at this problem from the other direction: [What is a non-capturing group? What does a question mark followed by a colon (?:) mean?](https://stackoverflow.com/questions/3512471/what-is-a-non-capturing-group-what-does-a-question-mark-followed-by-a-colon) — apsillers, Oct 18 '17 at 16:48
Or you can try this: [`'image\/([^']+)'(?=])`](https://regex101.com/r/r8ZfO8/2) — Gurmanjot Singh, Oct 18 '17 at 16:54
@WiktorStribiżew I think I am just to new to this, but from what I looked at the other post what you put would make it only return `'image'` would it not? I tried it and it worked, I just was wondering if you had some insight — Taylor Austin, Oct 18 '17 at 17:04

Using RegExp and match in JS getting back more than one match, but only want one

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