sprintf percent formatting

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

I basically want input 1/30, output is "Result: 3%".

Currently I'm doing it as below, which works for 33% but not for 3% (extra zero at the beginning, i.e. 03%). Is there a more elegant/intuitive way to do this than just using sprintf?

Thanks!

use strict;
use warnings;
use Test::More qw(no_plan);

my $one_third = 1/3;
my $percent = sprintf("%02d%%",$one_third*100);
is($percent,"33%"); 
print "Result: $percent\n";

my $one_thirtieth = 1/30;
$percent = sprintf("%02d%%",$one_thirtieth*100);
is($percent,"3%"); 
print "Result: $percent\n";
[download]

Comment on sprintf percent formatting Download Code

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Re: sprintf percent formatting by tbone1 (Monsignor) on Aug 17, 2005 at 12:50 UTC
Change the sprintf statements to use "%2d%%" instead of "%02d%%". The leading 0 forces left-padding of 0s on numbers. -- tbone1, YAPS (Yet Another Perl Schlub) And remember, if he succeeds, so what. - Chick McGee	[reply]
Re: sprintf percent formatting by b10m (Vicar) on Aug 17, 2005 at 12:50 UTC
`sprintf` is probably what you want, yet give it a slightly altered input and it'll work: `use strict; use warnings; use Test::More qw(no_plan); my $percent = sprintf("%d%%",(1/3)100); is($percent,"33%"); print "Result: $percent\n"; $percent = sprintf("%d%%",(1/30)100); is($percent,"3%"); print "Result: $percent\n";` [download] Instead of '%02d%%', I now use '%d%%' which seems to be what you want. -- b10m All code is usually tested, but rarely trusted.	[reply] [d/l]
Re: sprintf percent formatting by derby (Abbot) on Aug 17, 2005 at 12:49 UTC
How about printf and dropping the 0. `use strict; use warnings; my $one_third = 1/3; printf( "Result: %2d%%\n", $one_third * 100 ); my $one_thirtieth = 1/30; printf( "Result: %2d%%\n", $one_thirtieth * 100 );` [download] -derby	[reply] [d/l]
Re^2: sprintf percent formatting by xdg (Monsignor) on Aug 17, 2005 at 13:14 UTC
How about just specifying decimal precision on the sprintf: `> perl -e 'print sprintf("%.0f%", 1/30100)' 3%` [download] Update: Aside from sprintf formatting, if what you're really trying to do is compare two floating point numbers for Test::More, you might want to look at Test::Number::Delta, which I wrote to avoid that kind of roundabout way of comparing numbers. E.g. `use Test::More tests => 1; use Test::Number::Delta within => .01; my $percent = 1/30; delta_ok( $percent, 0.03, 'values within 1%');` [download] -xdg Code written by xdg and posted on PerlMonks is public domain. It is provided as is* with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.	[reply] [d/l] [select]
Re^2: sprintf percent formatting by Roger (Parson) on Aug 17, 2005 at 12:59 UTC
Well, I don't believe the OP wants to drop the leading 0. The OP wants to know if there is a more elegant way to write a test case without using sprintf. Correct me if I am wrong.	[reply]
Re^3: sprintf percent formatting by tphyahoo (Vicar) on Aug 17, 2005 at 13:14 UTC
No no, I was happy with all three answers about dropping the 0. In fact, it was a testing situation that led me to post this question, but I am okay with my current Test::More solution, which winds up along the lines of `......code..... ok($keyword_density >= $min_keyword_density,"Keyword density " . sprin +tf("%2d%%",$keyword_density100) . ", minimum " . sprintf("%2d%%",$mi +n_keyword_density100) );` [download] This seems elegant enough for me, but as always I welcome suggestions.	[reply] [d/l]
Re^4: sprintf percent formatting by Util (Priest) on Aug 17, 2005 at 14:44 UTC


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