$message vs. $$message in PHP.

$message is a variable with a fixed name. $$message is a variable whose name is stored in $message. For example: $Message means simple variable store data. $$Message means variable variable. That is, a variable name which can be set and used dynamically $Message = 'hello'; print $Message; // print hello $$Message = 'world'; means $hello ='world'; now if u print $$Message; menas $hello;// print world; if u print $Message $($Message); // print hello world;