CODEWITHSUNDEEP
regexregex-negation
dovid
dovid

Reputation: 6491

Negative Lookahead how use

the texts:

1a2c3

i want all number which does not have a berfore it: 1, 3

I thought it was a classic case of negative lookahead:

(?!a)[1-9]

but the result is: 1,2,3

What is my mistake? And what way do I need to find only those who have no match whatsoever?

Upvotes: 0

Views: 41

Answers (1)

Joseph Marikle
Joseph Marikle

Reputation: 78590

Use a negative look-behind: ?<!

/(?<!a)[1-9]/

https://regex101.com/r/E7k5t4/1

Upvotes: 2

Related Questions