Question

I want to be able to search for a certain word in a string, and append and prepend characters to every instance of that word.

example:

I like cats, cats are awesome! I wish I had cats!

becomes:

I like (cats), (cats) are awesome! I wish I had (cats)!

I know I could use

str_replace( 'cats', '(cats)', $string );

but I would have to write “cats” twice.
I want a method that only requires me to write it once.

Answer 1

use a preg_replace() with back references: http://php.net/manual/en/function.preg-replace.php

preg_replace("/cats/smi","($0)",$string);