Question

I need to search and replace in a string, I want to replace the last occurrence of a string.

Here’s my working code (which just does a normal search/replace):

PREG_REPLACE("/(\b{$abbr}\b)/i", "$long" , $street_address)

Example of expected results:

• $street_address = “123 St Martin St”
• $abbr = “St”
• $long = “Street”
• return = “123 St Martin Street”

I want only the last occurrence of St replaced with Street.

Answer 1

You can use negative lokahead like this:

$str = "123 St Martin St";
$abbr="(\b)St(\b)";
$long="Street";
var_dump(preg_replace("~$abbr(?!.*?$abbr)~", "$1" . $long . "$2", $str));

OUTPUT:

string(20) "123 St Martin Street"