How to give format to numbers?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I need to format any of these formats of numbers to a decimal with two places (#.00)...so these numbers:

86902
.50
2.
165.0
0.666666666
[download]

would come out the other side as:

86902.00
0.50
2.00
165.00
0.66
[download]

now, i have a series of regexes that gets the job done...but its ugly and a little bruteforce-ish:

# if value is '#' then append ".00"
$curr .= ".00" if $curr =~ m/^\d+$/;
    
# if value is '.#' then prepend "0"
$curr = "0".$curr if $curr =~ m/^\.\d+$/;
    
# if value is '#.' then append "00"
$curr .= "00" if $curr =~ m/^\d+\.$/;
    
# if value is '#.0' then append "0"
$curr .= "0" if $curr =~ /^\d+\.\d$/;
    
# if necessary, truncate to 2 decimal places
$curr =~ s/^(\d+\.\d{2})\d+$/$1/;
[download]

so, this works just fine, its just not every elegant and i'm a stickler for clean code. is there a better way?

also, if theres an easy way to round to rather than truncate to 2 decimal places (so i'd get 0.67 instead of 0.66), by all means let me know!

2006-06-23 Retitled by planetscape, as per Monastery guidelines

( keep:0 edit:13 reap:0 )

Original title: 'a *cleaner* way to do it?'

Comment on How to give format to numbers? Select or Download Code

Replies are listed 'Best First'.
Re: How to give format to numbers? by ikegami (Patriarch) on Jun 22, 2006 at 15:00 UTC
Use `sprintf`/`printf`: `$curr = sprintf('%.2f', $curr);` [download] It rounds.	[reply] [d/l] [select]
Re: How to give format to numbers? by philcrow (Priest) on Jun 22, 2006 at 15:01 UTC
I'd use sprintf: `my $num = 5.26256; my $formatted = sprintf( "%.2f", $num ); print "$formatted\n";` [download] Phil	[reply] [d/l]
Re: How to give format to numbers? by Asim (Hermit) on Jun 22, 2006 at 15:02 UTC
format any of these formats of numbers to a decimal with two places (#.00) `printf` and it's good friend `sprintf` were born to do your bidding along these lines, my friend. I'd recommend a good, long look at perlfaq4; it touches upon this issue, as well as your rounding problems. Good luck! Edited for quick grammar cleanup... ----Asim, known to some as Woodrow.	[reply] [d/l] [select]
Re: How to give format to numbers? by Mutant (Priest) on Jun 22, 2006 at 16:49 UTC
As mentioned, sprintf/printf may suit your needs. Another option is Number::Format, which will do all that, and a lot more.	[reply]
Re: How to give format to numbers? by Hue-Bond (Priest) on Jun 22, 2006 at 15:01 UTC
You want printf: `while (<DATA>) { printf "%1.2f\n", $_; } __DATA__ 86902 .50 2. 165.0 0.666666666` [download] Update: Better sprintf, as has been pointed out -- David Serrano	[reply] [d/l]