A simplistic version is:

use warnings;
use strict;

for (qw($100000000.00 $100.00 $1000.00)) {
    my $value = reverse $_;

    $value =~ s/(\d{3})(?=\d)/$1,/g;
    $value = reverse $value;
    print "$_ => $value\n";
}
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Prints:

$100000000.00 => $100,000,000.00
$100.00 => $100.00
$1000.00 => $1,000.00
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However that (as you can see) doesn't obey the convention that $1000.00 does not get a comma.

Is there a way to do this with sprintf, since I already format the number with it, like this:



my $_accountBalance = $_db->{acct_bal};
print qq~Current Account Balance: ~ . sprintf('$%.2f', $_accountBalanc
+e) . qq~! As of $_date~;
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When I used that code to format the number without the sprintf, it put the commas in the correct position, but after I got the correct format then used my sprintf it truncated everything down to 3 digits and the .xx

Thanks again.

Do the formatting in a sub:

use warnings;
use strict;

print "Current Account Balance: ", asDollars ($_), "\n"
    for 100000000, 100, 1000;


sub asDollars {
    my $value = reverse sprintf '$%.2f', shift;
    $value =~ s/(\d{3})(?=\d)/$1,/g;
    return scalar reverse $value;
}
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Prints:

Current Account Balance: $100,000,000.00
Current Account Balance: $100.00
Current Account Balance: $1,000.00
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Note that scalar is required in the return statement because reverse may otherwise see a list context.

---

Perl is environmentally friendly - it saves trees

Looks like Number::Format would be an easy way to go. I haven't used it myself, but by my reading of the documentation, it would be as simple as:

use Number::Format ':subs';

for (qw($100000000.00 $100.00 $1000.00)) {
    s/^\$//;
    $_ = '$' . format_number( $_, 2, 2 );
    print;
}
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It's even easier if there weren't the dollar sign at the front.

See "How can I output my numbers with commas added?" in perlfaq5.

sub number_format {
   my $num = shift;
   return $num unless $num;
   return undef unless $num =~ /^[0-9\.+-]+$/;
   $num =~ s/^([\+-])?//;
   my $sign = $1;
   $num =~ s/\.([0-9]+)$//;   # must come before the call to abs(), be
+cause here
   my $dec = $1;              # a floating point value is still regard
+ed as a string by perl, even if it's 0.00.
   $num = abs $num;
   $num = reverse $num;
   $num =~ s/(\d{3})/$1\,/g;
   $num =~ s/\.$//;
   $num = reverse $num;
   $num .= ".$dec" if $dec;
   $num = "$sign$num" if $sign;
   $num;
}
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Cheers,

JohnGG

#!/usr/bin/perl -w
use strict;
use CGI::Carp qw(fatalsToBrowser);
use CGI qw(:standard);

my %_numbers = (
    1 => "2020283.40",
    2 => "02384829.94",
    3 => "1038.92",
    4 => "303.02",
);

print header();
foreach my $num (sort {$a <=> $b} keys %_numbers) {
    my $_number = format_number(sprintf('$%.2f', $_numbers{$num}));
    print qq~$num) $_number~, br();
}

sub format_number
{
    my $num = shift;
    $_ = reverse $num;
    s/(\d{3})(?=\d)(?!\d*\.)/$1,/g;
    return (reverse $_);
}
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