Here's a simple (and quite fast) one using substr: 

my $number = 132452345;
for ( my $i = -3; $i > -1 * length($number); $i -= 4 )
{
    substr( $number, $i, 0 ) = ',';
}

[download]

In reply to Re: How do I print a large integer with thousands separators? by Jaap
in thread How do I print a large integer with thousands separators? by miblo

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