CODEWITHSUNDEEP
regex
GML-VS
GML-VS

Reputation: 1100

Regex for fixed length string, starting with multiple words with different length

I'm trying to make a regex that matches a string that is exactly 10 characters in length and must start with either "ESZ", "XXZ", "H" or "A2/10". I tried something like this but I can't specify the total string's length because of the length variation in the starting words:

      ^(ESZ|XXZ|H|A2/10).{5,9}$

How to specify the total string's length to '10' in this case?

Upvotes: 0

Views: 399

Answers (1)

jrook
jrook

Reputation: 3519

Since the alternatives are so few, why not specify them all with ^(ESZ.{7}|XXZ.{7}|H.{9}|A2\/10.{5})$?

https://regex101.com/r/5BwTWP/1

EDIT:

This can alternatively be achieved by : (?=.{10}$)(ESZ|XXZ|H1|A2\/10)

https://regex101.com/r/5BwTWP/3

This regex first does a lookahead to make sure there are 10 chars in the string. Something like a check for string.length === 10 before regex matching should also do.

I still think the very first approach is the simplest and most efficient.

Upvotes: 2

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