I have a javascript regex that matches an incrementing numerical value using look ahead however, I feel this can be simplified.

I currently am using /^(?=[1-5]{5}$)(?=(?=.*([1]))(?=.*([2]))(?=.*([3]))(?=.*([4]))|(?=.*([2]))(?=.*([3]))(?=.*([4]))(?=.*([5])))\d+$/gm to identify if at least 4 digits in a 5 digit string have values that increment by 1.

Rules:

• Can only contain numbers 1-5 and there must only be 5 characters in the string = (?=[1-5]{5}$)
• 4 of the 5 numbers must increment by 1, they do not have to be grouped together.
• Here I have entered 4 literal groups for each potential incrementing 4 digit string
  • (?=.*([1]))(?=.*([2]))(?=.*([3]))(?=.*([4])) and (?=.*([2]))(?=.*([3]))(?=.*([4]))(?=.*([5])).
  • These are inside a look ahead with an or separator => (?=(?=.*([1]))(?=.*([2]))(?=.*([3]))(?=.*([4]))|(?=.*([2]))(?=.*([3]))(?=.*([4]))(?=.*([5])))\d+$

Here is an example of strings that match the regex:

12343 - 4 numbers increment in order starting at the 1

32142 - 4 numbers increment, but not in order starting with the 1

23451 - 4 numbers increment in order starting at the 2

52345 - 4 numbers increment in order starting at the 2

34152 - 4 numbers increment out of order, here we have 2 matches that are not in order, only one match is required

12345 - 4 numbers increment in order, here we have 2 matches that are both in order, only one match is required

My regex seems to work with my tests, however I just feel there is a more dynamic and cleaner approach to this that I am just not privy to as my regex skills are below par to say the least.