I decided to take up your challenge. Create a single regular expression to 'commify' a number. Here is my entry:

    $number =~ s/(\d+?)(?=(?:\d{3})+(?:\.|\z))/$1,/g;

Can anybody spot a case where this would not work?

Since the regular expression is looping in C code, rather than Perl code, I expect this solution to execute faster.

In reply to Re: "Commifying" a number by MarkM
in thread "Commifying" a number by Tanalis

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