How to make some parts of a regex pattern conditional?

Question

I checked this forum for a answer to my problem, but couldnt find. Experts please help.

I have a problem to validate a string say first name. I am given a set of rules w

Answer 1

Try this

[A-Za-z]+(?:[-'!` ]?[A-Za-z]+)?

You can check it online here: regexr

The second part

(?:[-'!` ]?[A-Za-z]+)? 

is a non capturing group, this group is because of the ? at the end optional.

Answer 2

Let Name be the regex for the simple name, Special the set of special characters (including the space). Then your final regex looks like

Name(SpecialName)?

Answer 3

What you need to do is repeat the text definition to have to exist 1 or more times AFTER the punctuation. This will work, but every name needs to be at least 2 characters (which seems reasonable..)

[A-Za-z]+[-'!` ]?[A-Za-z]+