print shift sort @array;

##</code><code>##

Type of arg 1 to shift must be array (not sort) at script.pl line 7, near "@array;"

##</code><code>##

my @a = ( 4, 1, 3, 2 );
my @b = sort @a;
print shift @b;

##</code><code>##

1. sort @a returns an array, namely the sorted version of @a.
2. shift takes an array as argument and returns a scalar.