Regex: Add space if letter is adjacent to a number

Question

I'm using PHP and not really good with regex. I need a preg_replace that can add a space if a letter or number is adjacent.

These are the scenarios:

mystreet12 -> mystreet 12
mystreet 38B -> mystreet 38 B
mystreet16c -> mystreet 16 c
my street8 -> my street 8

Thanks.

Answer 1

You could use lookarounds to match such positions like so:

preg_replace('/(?<=[a-z])(?=\d)|(?<=\d)(?=[a-z])/i', ' ', $str);

Depending on how you define "letter" you may want to adjust [a-z].

Lookarounds are required to make it work properly with strings like:

0a1b2c3

Where solutions without would fail.

Answer 2

Something like:

preg_replace("/([a-z]+)([0-9]+)/i","\\1 \\2", $subject);

Should get you far :)