Power of PHP extended to use a variable variables.
Example:
Sometimes it is convenient to be able to have variable variable names. That is, a variable name which can be set and used dynamically. A normal variable is set with a statement such as:
<?php
$a = 'hello';
?> A variable variable takes the value of a variable and treats that as the name of a variable. In the above example, hello, can be used as the name of a variable by using two dollar signs. i.e.
<?php
$$a = 'world';
?> At this point two variables have been defined and stored in the PHP symbol tree: $a with contents “hello” and $hello with contents “world”. Therefore, this statement:
<?php
echo "$a ${$a}";
?> produces the exact same output as:
<?php
echo "$a $hello";
?> i.e. they both produce: hello world.
me : yeay its me arun