PHP Regex expression to validate a name input

Question

As part of my validation I have the following regex expression:

 ^
# Prevent 3+ consecutive letters: 'wheee'
(?!\w*([a-zA-Z])\g{-1}{2,})
[a-zA-Z](?:[a-zA-Z]|'(?!')){0,}
# Words or '&' are space or hyphen separated
(?:
 [ -]
 # Prevent 3+ consecutive letters: 'wheee' (for rest of words)
 (?!\w*([a-zA-Z])\g{-1}{2,})
 (?:[a-zA-Z]|'(?!')){1,}
|
 [ -]
 &
)*$

I was wondering the effectiveness of the expression and/or possible pitfalls?

• mheinzerling: I'm missing a short explanation why you need this expression and what you try to achieve?

Answer 1

One possible pitfall is that several celebrities cannot pass your "validation" code. Do you really want Renée Zellweger and Goran Ivanišević being mad at you?

Answer 2

[a-zA-Z]

You use both lowercase and uppercase everywhere. This can possibly be symplified with (inline) modifiers:

(?i)[a-z]

Personally I use quantifiers as a "sugar" instead of explicit interval specifying:

{0,} ==> *
{1,} ==> +

• Vaishal Patel: would there be any speed or other benefit to using quantifiers as a "sugar" instead of explicit interval specifying?