printf function alternative? formatting without printing

[fraizerangus]

Hi Everyone Sorry for the rookie question but, I'm using

$n -= ($n * $u) * $u;

printf "%d\n", abs($n);

iterating through to get a result I want, but I want to save this result in an index of an array, but the above function just prints it to the screen I can't do anything with it?! to save the result and process it further is there anyway I can format it and save it as a string, in a for loop? e.g.

array [$i] = (printf "%d\n", abs($n));

many thanks and apologies if this question seems or sounds stupid to you?

[SankoR]

You're looking for sprintf.

[FunkyMonk]

Generally speaking, Perl treats numbers and stringified numbers as equal (ie perl -e "print 'equal' if '6.0' == 6" will print "equal"). So int will do just as good a job as sprintf.

[ww]

Both the advice from SankoR and, even more so, the observation by FunkyMonk are clearly on target. In the hope of offering some additional clarity:

printf produces output; sprintf merely formats

However, I'm perplexed by your use of "string" in the phrase "save it as a string" as well as by some other aspects of the question. For example, do you mean that $n and $u are floating point numbers (assumed below) or can they be ints; a mixture; or something else??

All the above leads me to send a question back: Does this come somewhere close to your intent?

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

# 816487

my $n = 3.123;
my $u = 3.678;
my $i= 0;
my (@array, $array);

for (1..10) {
    $n -= ($n * $u) * $u;
    $array[$i] = int(abs($n));
    $i++
}

for (@array) {
    print "$_ \n";
}

Output, for $n=3.123, $u=3.678

39
490
6140
76922
963664
12072486
151240294
1894690621
23736085384
297358177092

and for $n=3.123, $u=4.0

46
702
10540
158101
2371528
35572921
533593828
8003907421
120058611328
1800879169921

And another question: "Waaaay off? Helpful?" (I hope the latter.)

[toolic]

If you need even more capabilities than sprintf, you could reach for these CPAN modules:
Number::Format
Number::FormatEng

[ikegami]

If you're dealing with integers,

$array[$i] = abs($n);

If you're dealing with floats,

use POSIX qw( ceil floor );

$array[$i] = int(abs($n));            # Truncates
$array[$i] = sprintf('%d', abs($n));  # Rounds
$array[$i] = ceil(abs($n));           # Finds ceiling
$array[$i] = floor(abs($n));          # Finds floor

Add the "\n" when you print. There's no reason to store it in the array.

[ravi.s]

You might have to save the output and "push" those values into array instead of printing the value. Sample Code : <code>for ( condition ) { $n -= ($n * $u) * $u; push(@i,"$n"); }<code>

[mnooning]

Yes. sprintf FORMAT, LIST Just use sprintf instead of printf, and assign it to the array.