Multiple Assignments in perl

Following code represents multiple assignments in perl :-
1.  ($a, $b) = (123, "123");
Here :-
$a = 123
$b = "123"

2. ($a , @b) = (123, "123", "456");

Here :-
$a = 123
@b = ("123", "456");

Note :- Same effect when @foo =  (123, "123", "456");
            And code is changed to ($a, @b) = @foo;

3. (@b , $a) = (123, "123", "456");

Here :-
@b = (123, "123", "456");
and $a is undefined as perl is greedy language and @b will swallow up as much of the array passed.