Working with Dynamic variable names a/k/a Variable variables in PHP

Variable variables are one of my favorite things about PHP. PHP allows you to
use a variable to reference another variable. This comes in exceptionally handy
when you need to create variable names dynamically:

$variable = 'This is my variable'
$var      = 'variable'

echo $$var

Let’s say you have you have a variable that uses another variable as part of
the name:

$array         = range(1, 100
$format_json   = json_encode($array
$format_serial = serialize($array

$format   = 'json'
$variable = 'format_' . $format

echo $$variable

Granted this is a very simple example to demonstrate the functionality. Real
world usage could end up being more complex and really show off the power of
variable variables.