Question

I’ve got a street address like, for instance, “1234 West 23rd Street”. I’d like to blow out just the first street number and put spaces in between each number, like this: “1 2 3 4 West 23rd Street”.

Using the simple expression like "([0-9])" and replacing it with "$1 " almost works, except I want it to stop after the first space and not match, per the above example, the “23” in “23rd” as well.

Answer 1

This is possible with preg_replace and the pattern modifier ‘e’, which:

does normal substitution of backreferences in the replacement string, evaluates it as PHP code, and uses the result for replacing the search string

$str = '1234 West 23rd Street';
preg_replace('/^([[:digit:]]+)/e', "implode(' ', str_split('$1'))", $str);
// returns '1 2 3 4 West 23rd St'