SIMPLE way to write these?

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

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Re: SIMPLE way to write these? by choroba (Cardinal) on Feb 04, 2014 at 14:09 UTC
`for` also introduces a loop. The canonical way to print the numbers between 1 and 10 would be `for my $i (1 .. 10) { print "$i\n"; }` [download] Or, even, something like `use feature qw{ say }; say for 1 .. 10;` [download] With a while loop, you just have to initialize a counter, and then check its value against the final value in the loop condition: `my $i = 1; while (10 >= $i) { print $i++, "\n"; }` [download] The factorial is left as an exercise for the reader. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re^2: SIMPLE way to write these? by Anonymous Monk on Feb 04, 2014 at 14:13 UTC
Aham, I see, but how can you use a while loop to print all numbers between $number1 and $number2 ( I mean if they are both user-defined)?	[reply]
Re^3: SIMPLE way to write these? by choroba (Cardinal) on Feb 04, 2014 at 14:24 UTC
Ahem, just replace 1 (that is not followed by 0) with $number1; and similarly, replace 10 with $number2. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply]
Re^4: SIMPLE way to write these? by Anonymous Monk on Feb 04, 2014 at 14:36 UTC
Re^5: SIMPLE way to write these? by GotToBTru (Prior) on Feb 04, 2014 at 15:04 UTC
Some notes below your chosen depth have not been shown here
Re: SIMPLE way to write these? by tobyink (Canon) on Feb 04, 2014 at 15:20 UTC
Any C-style `for` loop: `for (INIT; COND; POST) { BODY; }` [download] Can always be rewritten as a `while` loop like this: `INIT; while (COND) { BODY; POST; }` [download] So your loop can be written as: `$j=1; while ($j<=10) { print "$j\n"; $j++; }` [download] However, in Perl there are more idiomatic ways of writing it. For example: `print "$_\n" for 1..10;` [download] Or, if you've got a recent version of Perl, and enable the "say" feature: `say for 1..10;` [download] `use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name`	[reply] [d/l] [select]
Re: SIMPLE way to write these? by johngg (Canon) on Feb 04, 2014 at 16:03 UTC
It is also worth mentioning that `while` can be used as a statement modifier. `$ perl -Mstrict -Mwarnings -E ' my $i = 1; say +( $i ++ ) while $i <= 10;' 1 2 3 4 5 6 7 8 9 10 $ perl -Mstrict -Mwarnings -E ' my $i = 1; say do { $i ++ } while $i <= 10;' 1 2 3 4 5 6 7 8 9 10 $` [download] I hope this is helpful. Cheers, JohnGG	[reply] [d/l] [select]
Re: SIMPLE way to write these? by karlgoethebier (Abbot) on Feb 04, 2014 at 14:39 UTC
In the only lecture i had about algorithms the professor told us: "Shure, you can cheat but then you need to explain it to me..." ;-) `#!/usr/bin/perl use strict; use warnings; my ( $c, $f ) = ( 10, 1 ); $f *= $c-- while $c > 0 ; print $f; __END__ karl@host ~ $ ./factorial.pl 3628800` [download] Wolfram Alpha Regards, Karl «The Crux of the Biscuit is the Apostrophe»	[reply] [d/l]
Re: SIMPLE way to write these? by 2teez (Vicar) on Feb 04, 2014 at 14:27 UTC
..Use a loop to write all numbers between* 1 and 10..* Using the C for loop like you did, included 1 and 10. I thought the question says numbers BETWEEN? If they are included, well and good but if not, you might have to write `for (my $j = 2; $j < 10; $j++){...}` OR better `print $_,$/ for 2 .. 9` If you tell me, I'll forget. If you show me, I'll remember. if you involve me, I'll understand. --- Author unknown to me	[reply] [d/l] [select]
Re: SIMPLE way to write these? by pvaldes (Chaplain) on Feb 04, 2014 at 15:18 UTC
`foreach (1..10){print "$_\n"}` or, with while: `my $i = 0; while ($i < 11){++$i; print $i};` as Choroba said before	[reply] [d/l] [select]