What is the meaning of the '?', '()', and ':' symbols in PHP?

Question

I\'ve finally remembered what to ask. I never really got what : and ? do when a variable is being defined like this:

$ip = ($_SERVER[\'HTTP_X_FORWARDED_FOR\'         


        

Answer 1

It's known as a ternary operator and is shorthand for (in your case):

if($_SERVER['HTTP_X_FORWARD_FOR'])
{
    $ip = $_SERVER['HTTP_X_FORWARD_FOR'];
}
else
{
    $ip = $_SERVER['REMOTE_ADDR'];
}