This is something that ASP does not have. — Variable Variables.
It takes the content of a variable and use it as variable names.
$a = ‘foo’;
$$a = ‘bar’;
the above statement is equivalent to:
$foo = ‘bar’;
Two consecutive $ signs ($$a = ‘bar’) tells PHP to take the value of the variable (in our example, $a which contains ‘foo’) and use that as the variable name, then assign ‘bar’ to that variable.
Why would anyone need to do that? I don’t know. What would be a good real-world example use for this feature? Neat feature, just not sure how useful this would be.