arrays and foreach loops to work with input vars more efficiently

Question

If I have 20 user input vars and want to work between $var[0..19], $_SESSION['var'[0..19]], & $_POST['var'[0..19]], such as:

$var0 = $_SESSION['var0'] = $_POST['var0'];

How could I do this efficiently using arrays and foreach loops?

Additional details:

So initially I have been thinking to try something like:

$inputVars = array('var1'=>$var1, 'var2'=>$var2, 'var3'=>$var3, 'var4'=>$var4, 'var5'=>$var5)

$inputVarsS = array($_SESSION['inputVars = array('svar1'=>$_SESSION['var1']'], 'svar2'=>$_SESSION['var2'], 'svar3'=>$_SESSION['var3'], 'svar4'=>$_SESSION['var4'], 'svar5'=>$_SESSION['var5'])

$inputVarsP = array($_POST['inputVars = array('pvar1'=>$_POST['pvar1']'], 'pvar2'=>$_POST['pvar2'], 'pvar3'=>$_POST['pvar3'], 'pvar4'=>$_POST['pvar4'], 'pvar5'=>$_POST['pvar5'])

and then I guess I could do something like:

$inputVarsS['svar1'] = $inputVarsP['pvar1'];

to set session value svar1 to posted value pvar1. But I am thinking there really must be a more efficient way to do these kinds of assignments.

I think I could just easily have $inputVars array and assign either POST SESSION values to the keys, but what if I want to have POST and SESSION values available simultaneously? Then I assume I need multiple arrays?

Answer 1

You can use $$ to define a variable name, but I think it's better to use an array $vars.

With $var0, $var1, ...., and you can access them like echo $var4

foreach(range(0, 19) as $index)
{
  $var = 'var' . $index;
  $$var = $_SESSION[$var] = $_POST[$var];
}

With array $vars, and access them with echo $vars[4]

foreach(range(0, 19) as $index)
{
  $var = 'var' . $index;
  $vars[$var] = $_SESSION[$var] = $_POST[$var];
}