Why do I get a decimal point in my BigInt numbers?

Question

Adding 15 digit numbers like 999999999999990 in Perl produces results with a period such as 1.9999999999999e+. When using substr it still produces 1.99999999999, and when using BigInt the result still has a period. What is the correct Perl syntax for Perl 5.8.7 to get the result without the period?

use BigInt;
$acct_hash = substr(($acct_hash + $data[1]),0,15);

BigInt.pm -> /opt/perl5.8.7/lib/5.8.7/Math/BigInt.pm
BigInt -> /opt/perl5.8.7/lib/5.8.7/Math/BigInt.pm

Answer 1

Use the bigint pragma to get transparent use of Math::BigInt:

#!/usr/bin/perl

use strict;
use warnings;


print 999999999999990 + 999999999999990, "\n";

use bigint;

print 999999999999990 + 999999999999990, "\n";