what does two $ in a row ($$) means?

spectacell

I know when you write on $ infront a text it's a variable but when you write two $$ infront of a word what is it then?

example:

$$something

Regards
/Emil Hansson

swallace

It's a variable variable...

http://www.devshed.com/Server_Side/PHP/VarVar/page1.html

This article is good for explaining them...

bernouli

<?php
$string= "name";
$name= "bernouli";

echo $string;
//you get "name"

echo $$string;
//you get "bernouli"
?> 😃

itguysam

This is very usefull for creating scripts that dyanmically create and collect input from an array of html input forms.
In page 1 you can put something like this with a loop for id

<INPUT TYPE="TEXT" NAME="<?php print("$str$id");$id++;?>"

and then on page two you can do soemthing like this to collect the input. Notice how the two $'s allow you to create tokens for arbitrary HTML post info.

for($arays=0;$arays<$num;$arays++){
        $htoken= Heigth.$arays;
        $wtoken= Width.$arays;
        $id=0;
        $str=chr(ord('a')+$out++);
        for($loop=0;$loop<$$htoken;$loop++){
                for($loop2=0;$loop2<$$wtoken;$loop2++){
                $tag=$str.$id++;
                $aray[$arays][$loop][$loop2]=$$tag;
                }
        }
}

spectacell

thank you for the answers...they made a bit more clear about it even if I didn't quite understand the examples. Probably I will soon when my PHP skill improves.

regards
/Emil

br__ken

to further bernouli's point:

$larr="child";
$child=array("c","h","i","l","d");
$parent=array("p","a","r","e","n","t");

print_r($larr);
// prints "child"

echo "<br>";

print_r($$larr);
// prints the $child array
echo "<br>";
// the EXACT SAME as :
eval("print_r(\$" . $larr . ");");

if you understand eval(), then $$ is almost the same.. with eval what it does is turn "print_r(\$" . $larr . ");" into a php command which would = print_r($child);

with print_r($$larr), php takes the '$$' and then evaluates "child" (val of $larr) as $child.. so if $larr="crack", then $$larr would = $crack..

in layman terms: just divide the 2 $'s so it becomes $($larr)..then just take that literally.. as $(child) or $child.

hope that made some sense 🙂