How to let regex ignore everything between brackets?

Question

Consider the following string:

I have been driving to {Palm.!.Beach:100} and it . was . great!!

I use the following regex to delete all pun

Answer 1

Try this

[^a-zA-Z {}]+(?![^{]*})

See it here on Regexr

Means match anything that is not included in the negated character class, but only if there is no closing bracket ahead without a opening before, this is done by the negative lookahead (?![^{]*}).

$string preg_replace('/[^a-zA-Z {}]+(?![^{]*})/', '', $string);