Variable variables in PHP - What is their purpose?

Question

In PHP there\'s a functionality officially called \"Variable Variables\" where one can assign variable variables. A variable variable takes the value of one variable as the

Answer 1

According to @Faiz answer (which I accepted as the formal answer to my question) I created the following sample example.

If I had the class Customer:

class Customer
{
  public $firstname;
  public $lastname;
  public $country;
  public $gender;
  ...
}

and the web HTML form with INPUT/SELECT fields having names 'firstname','lastname','country', 'gender'...

  
  
  
    Albania
    Belgium
    Croatia
    ...
  
  Man
  Woman
  ...
  

usually in my action script I would map these form fields into class variables one by one as:

$Customer=new Customer();
$Customer->firstname=$_POST['firstname'];
$Customer->lastname=$_POST['lastname'];
$Customer->country=$_POST['country'];
$Customer->gender=$_POST['gender'];
...
$Customer->create();

But using variable variables I can easily map all associative array values (there could be a lot of them which is error prone) into class variables using the following one line foreach loop;

$Customer=new Customer();
foreach($_POST as $key=>$value) $Customer->$key=$value;
$Customer->create();

Note: For the sake of answer (logic) simplicity and clearness I omitted $_POST values sanitization.