PHP replace string after using file_get_contents

Question

Hi I am looking to replace words in an html email I am loading via file_get_contents

Here is my code:

Answer 1

$message = str_replace("$SAD", "HAPPY", $message);

needs to be:

$message = str_replace('$SAD', "HAPPY", $message);

Otherwise PHP will interpret it as the variable $SAD. See this post for an explanation on the difference between single and double quotes.