JavaScript RegEx not ending with (.js|.jsx|.scss)

Question

I want to implement a JavaScript RegEx that not ending with (.js|.jsx|.scss), execution result like below, but no operator ! before RegEx.

!/(.js|.jsx|.scss)$/

Possible duplicate of [Regex that matches anything not ending in .json](https://stackoverflow.com/questions/21962329/regex-that-matches-anything-not-ending-in-json) and [Regex for matching string not ending or containing file extensions](https://stackoverflow.com/questions/39007246) — adiga, Feb 02 '19 at 12:05

score 4 · Accepted Answer · answered Feb 02 '19 at 12:04

4

You need to use a negative look ahead with alternations to reject the strings that end with those extensions you mentioned in your post. Try this regex,

^(?!.*(?:\.jsx?|\.scss)$).*$

Demo

var arr = ['abc.js','xyz.jsx','ddd.scss','abc.jsa','xyz.jsxa','ddd.scssd'];

for (s of arr) {
console.log(s+' --> '+/^(?!.*(?:\.jsx?|\.scss)$).*$/.test(s));
}

answered Feb 02 '19 at 12:04

Pushpesh Kumar Rajwanshi

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1

Thank you, it works. I want to know why `?:` is required in the given RegEx? If `?:` removed, it could also work well. – licaomeng Feb 02 '19 at 14:56
1

@licaomeng: `?:` is just used to make a group as non-capturing group as by default a group `()` is a capturing one and yes without `?:` also it will work fine. In general it is a good practice to make a group as non-capturing unless you really need the group (say for back referencing or group text capture) as it makes the group more performant. – Pushpesh Kumar Rajwanshi Feb 02 '19 at 15:01
1

It is clear now, thank you. – licaomeng Feb 02 '19 at 15:15
Glad to help :) – Pushpesh Kumar Rajwanshi Feb 02 '19 at 15:15

Code Maniac · Answer 2 · 2019-02-02T12:11:40.753

0

You can use this

^(?!.*\.(?:jsx?|scss)$).*$

^ - Anchor to start of string.
(?!.*\.(?:jsx?|scss)$).* - Condition to check jsx, js and scss
$ - End of string.

Demo

edited Feb 02 '19 at 12:11

answered Feb 02 '19 at 12:04

Code Maniac

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5
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JavaScript RegEx not ending with (.js|.jsx|.scss)

2 Answers2