my ($x, $y, $z); ($x, $y, $z) = f(); # if f() returns (2, 3, 7) then it is nearly the same as $x=2; $y=3; $z=7; ($x, $y, $z) = f(); # if f() returns (2, 3, 7, 9), then ignore 9 ($x, $y, $z) = f(); # if f() returns (2, 3); then $z will be undef

A regular question on job interviews: How can we swap the values of 2 variables, let say $x and $y?