See perlfaq4: "Does Perl have a round() function? What about ceil() and floor()? Trig functions?" In particular, take a look at the ceil function in POSIX.

Update: Don't forget about Super Search, which found a particularly relevant thread: Rounding up nearest ten, hundred etc. :-)

I hope ceil/floor is used for decimal numbers conversion. But I have only integers that last 3 digits rounded to next 100.

use strict;
use warnings;
use POSIX qw( ceil );

my $round_to = 100;

for( 78345, 5674 )
{
    print "$_ -> ", ceil( $_/$round_to ) * $round_to, "\n";
}
[download]

Output:

78345 -> 78400
5674 -> 5700
[download]

Take a look at the thread I mentioned in my previous post. There are quite a few examples to help you.

I might have done this

$num = 235634;
 
if (length($num) >=3 ) {
    $var = substr($num,-2,2);
     if ( !$var eq '00')
     {
        $var1 = 100 - $var;
        $num +=  $var1;
     }
     print $num;
}
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I guess this will work....
$a is the number to be rounded

#!/usr/bin/perl -w

$a=78345;
$b=100;
$c=$a/$b;
$d=$c;
$c=~s/\..*//;
if( $d > $c ){
$c++;  }
$c*=100;
print $c,"\n";
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$c will have the result

my $c = 786733; 
my $rounded = 100 * int(($c+ 50) / 100);
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my $c = 786001;
print 100 * int(($c + 99) / 100);
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# Rounders.pm
# 
#       ========
package Rounders;
#       ========

use strict;
use warnings;

use Exporter;
our @ISA = qw{Exporter};
our @EXPORT = qw{rndZero rndPlaces};

use POSIX qw(ceil floor pow);

#   -------
sub rndZero
#   -------
{
    my $val = shift;
    my $rounded = $val < 0 ?
       POSIX::ceil($val - 0.5) : POSIX::floor($val + 0.5);
    return $rounded;
}

#   ---------
sub rndPlaces
#   ---------
{
    my($val, $places) = @_;
    my $rounded =
       rndZero($val * POSIX::pow(10.0, $places)) /
       POSIX::pow(10.0, $places);
    return $rounded;
}

1;
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a test script to demonstrate usage

#!/usr/local/bin/perl
#
use strict;
use warnings;

use Rounders;

my $val = 724934.817084;
print qq{Original value - $val\n};

print
   q{Rounded to whole number - },
   rndZero($val),
   qq{\n},
   qq{Rounded to decimal places\n};

printf qq{     %2d - %s\n},
   $_, rndPlaces($val, $_)
   for -4 .. 4;
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and the results

Original value - 724934.817084
Rounded to whole number - 724935
Rounded to decimal places
     -4 - 720000
     -3 - 725000
     -2 - 724900
     -1 - 724930
      0 - 724935
      1 - 724934.8
      2 - 724934.82
      3 - 724934.817
      4 - 724934.8171
[download]

I hope this is of use.

Cheers,

JohnGG

#!/usr/bin/perl -w
use strict;

my $num = 786603;
my $rem = $num % 100;
$num += (100 - $rem) if ($rem > 0);
print $num."\n";
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Thanks - I'm using this in my code!

Hi, how about this one?
This is much more flexible by changing the value of $digit and simple in a one line.

function roundup($number, $digit = 100)
{
  return ( is_numeric($number) && is_numeric($ digit) ) ? (ceil($numbe
+r/$ digit)*$digit) : false;
}
[download]

Please feel free to contact me at chae@azstrada.com if you have any questions.
Chae from Seoul Korea.

$num = 486733;

$num =~ /(\d{3})$/;
my $rnd = $1 / 100;
$rnd = sprintf "%.0f", $rnd;
$rnd .= '00';
$num =~ s/$1/$rnd/;
[download]

• How do I round a number?
• How do I print/round a number to a given number of decimal places?

-Scott