Advice on First Perl Script

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

Hi Perl Monks. I am learning Perl. this is my first script please comment. Thanks

#!c:/perl/perl.exe
print "My first Perl script\n"; ##the first line in the world of perl.
print "\n";

print "Please tell me the multiplication table required: "; ## your in
+put  
$num=<STDIN>;

print "Please tell me the multiplication Factor ( if you put more than
+ 100,make sure you have a big screen!  )        : ";
$y=<STDIN>;
## the Multipling factor 
for ($x=1;$x<=$y; $x++)
    {
        $tab=$num*$x;
print "the table is :   $tab \n";
    }
[download]

2006-05-04 Retitled by Corion, as per Monastery guidelines
Original title: 'Hozefa'

Comment on Advice on First Perl Script Download Code

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Re: Advice on First Perl Script by McDarren (Abbot) on May 04, 2006 at 10:49 UTC
Try this. Note the comments in the code and see below for some references for further reading: #!c:/perl/perl.exe # ALWAYS use strict and warnings (see: strict, warnings) use strict; use warnings; # In general, keep comments on separate lines from your code # the first line in the world of perl. print "My first Perl script\n\n"; # Declare the variables, and make them descriptive my ($multiplier, $max_number); # Get some input from the user # Lets also validate it (we are only interested in "numbers") # See perlre & perlretut while (1) { print "Please tell me the multiplication table required: "; chomp($multiplier=<STDIN>); # If it's a number, exit the loop last if $multiplier =~ /^\d+$/; } # Same as above while (1) { # The following line wraps in a standard DOS window, so lets sprea +d it # over a couple of lines print "Please tell me the multiplication Factor\n", "(if you put more than 100, make sure you have a big screen!) + : "; chomp($max_number=<STDIN>); last if $max_number =~ /^\d+$/; } # Now, print out the table # Use a "perlish" loop rather than a C-style one # By doing it this way, we don't need the loop variable # And we can instead just operate on $_ print "\nThe table is:\n\n"; for (1 .. $max_number) { print "$_ X $multiplier = ", $_*$multiplier, "\n"; } [download] References: strict, warnings, chomp, perlre, perlretut, print Cheers, Darren :)	[reply] [d/l]
Re: Hozefa by felonius (Scribe) on May 04, 2006 at 09:49 UTC
hi there, Well I'll start the responses off with the usual... `use strict; use warnings;` [download] That should give you some interesting feedback to investigate when a script doesn't work ;-) You could also use chomp on $num and $y to remove carriage returns etc. ie `chomp($num = <STDIN>);` [download] I'm sure there are some more experienced monks who will contribute further. Also check out some of the tutorials - they're very good. (So is the O'reilly book - Learning Perl)	[reply] [d/l] [select]
Re: Advice on First Perl Script by Praveen (Friar) on May 04, 2006 at 09:35 UTC
Try This `$y=10; for ($x=1;$x<=$y; $x++) { print "$x -->\t"; foreach (1..$y) { $result = $x*$_; print "$result\t"; } print "\n"; }` [download] Change $y if required Rds/Praveen	[reply] [d/l]
Re: Advice on First Perl Script by jwkrahn (Abbot) on May 04, 2006 at 23:41 UTC
You should get into the habit of using lexical variables instead of package variables, so: `$num = <STDIN>;` [download] Would become: `my $num = <STDIN>;` [download] While perl supports C style for loops it is usually preferred to use perl's for loops, so: `for ( $x = 1; $x <= $y; $x++ )` [download] Would become: `for my $x ( 1 .. $y )` [download]	[reply] [d/l] [select]