CODEWITHSUNDEEP
regex
user11480180
user11480180

Reputation:

How to get everything before the dash character in regex?

I have strings of the following form:

en-US //return en

en-UK //return en

en //don't return

nl-NL //return nl

nl-BE //return nl

nl //don't return

I would like to return the one's that are indicated in the code above. I tried .*\- but this returns en-. How do I stop returning before the slash? So only return en? I'm testing it here.

Upvotes: 1

Views: 2877

Answers (3)

The fourth bird
The fourth bird

Reputation: 163207

One option is to use a capturing group at the start of the string for the first 2 lowercase chars and then match the following dash and the 2 uppercase chars.

^([a-z]{2})-[A-Z]{2}$

Regex demo

If you want to capture multiple chars [a-z] (or any character except a hypen or newline [^-\r\n]) before the dash and then match it you could use a quantifier like + to match 1+ times or use {2,} to match 2 or more times.

^([a-z]{2,})-

Regex demo

Upvotes: 3

nettingGale
nettingGale

Reputation: 11

.+?(?=-) as a regular expression should do what you are asking.

Where

. matches any character

+? matches between one and infinity times, but it does it as few times as possible, using lazy expansion

and

(?=-) Is a positive look ahead, so it checks ahead in the string, and only matches and returns if the next character in the string is - but the return will not include the value -

Upvotes: 1

benvc
benvc

Reputation: 15120

You could use a positive lookahead.

.*(?=-)

If you are always specifically looking for 2 lowercase alpha characters preceeding a dash, then it is probably a good idea to be a bit more targeted with your regex.

[a-z]{2}(?=-)

Upvotes: 2

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