my @array = (1, 2, 3, 4);
my $val = ($array[0]) | ($array[1]<< 8) | ($array[2]<<16) | ($array[3]<<24);
printf "%d\n", $val;

##</code><code>##

my @array = (1, 2, 3, 4);
my $val = unpack 'L', pack 'C4', @array;
printf "%d\n", $val;