sub argComplex {
    my $value1 = shift;  # shift along acts on @_ so its the same as @_[0];

    my @construct = &constructComplex($value1);

    my $real1    = @construct[0];
    my $complex1 = @construct[2];

    return atan2($complex1, $real1);
}

my $real1;
my $z;

$real1 = 1;
$z = 1 + i;

print $real1 * argComplex($z);