2 or more $ in front of a variable

[x_maras]

Hi,

 

I saw in a code a variable with 2 dollars.

Couldnt be wrong because the code was working,

but I tried this by my self:

 

<?php
$something = "bla test";
$$something = $something;
echo $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$something;
?>

 

and it works it prints "bla test".

 

But, if you change the second line, for example : $$something = "print this";

it gives an error. The same happens if you change the name of the second variable:

 

<?php
$something = "bla test";
$$thing = $something;
echo $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$thing;
?>

This also gives an error.

 

Does anyone knows what exactly this does?

[RichardRotterdam]

The double dollar is a variable variable.

 

variables.variable

Personally I don't really see the point of using them I rather use arrays. But you could use them.

[avvllvva]

Here is the use of $$,

<?php
$testing = "The actual content of string";
$something = "testing";
echo $$something ;
?>

[PFMaBiSmAd]

Variable variables take three times longer to access than an array variable does, they should not really be used.