Using a list /array is almost similar to using a variable.
we do not need to swap string, numbers will be good enough

Using Arithmetic Operation it just can swap int or float type data.

But if we use Bitwise operation it can swap both number and string.

But it cannot swap any array, class; But if we use List it can swap everything. It can swap number, string, array and also can swap a class 

Array swap sample :
‘one’);
$y = array(’b’ => ‘two’);

list($x,$y) = array($y,$x);

echo ‘X : ‘;
print_r($x);
echo ‘Y : ‘;
print_r($y);
?>

Output:
X :
Array
(
[b] => two
)
Y :
Array
(
[a] => one
)

Class swap :
<?php

class a
{
public $name = ‘alu’;
}
class b
{
public $name = ‘begun’;
}

$x = new a();
$y = new b();

list($x,$y) = array($y,$x);

echo ‘X : ‘;
var_dump($x);
echo ‘Y : ‘;
var_dump($y);
?>

so list is better …

list($a, $b) = array($b, $a)

it will also swap values of two variables without using a third one - the php way!