Re: Chess Board Single Loop

[Anonymous Monk]

my %CHESS; foreach (1...8) { $CHESS{$_}{$_} = $_*$_ };

[xantithor]

For the fun of it I want to try the same thing, however with random variable numbers.

#!/usr/bin/perl -w

use strict;

my $num1;
my $num2;

print "Enter in a whole number: ";
chomp ($num1 = <STDIN>);

print "Enter in another whole number: ";
chomp ($num2 = <STDIN>);
print "\n";

foreach ( $num1 .. $num2 ) {
  print "$_ ";
  print "\n" if ( $_ == ($num1 +4) );
  }

the last line of the code I am stumped on. I want it to start a new line after five numbers. It works if the number range is smaller than 10 numbers, however if I expand past 10 numbers it keeps on trucking.

[kcott]

$_ == ($num1 +4) will only ever be true once at most; if $num2 is small enough, it will never be true.

Given the number of times "%" (the modulo operator) has been mentioned in this thread, I'm surprised you haven't looked into it. [follow the link I've provided for details of this operator]

To produce a newline after every 5 numbers, you'll need to change

print "\n" if ( $_ == ($num1 +4) );

to something like

print "\n" unless ($_ - $num1 + 1) % 5;

You may need to sit down with paper and pencil to understand why this code works. That would probably be time well spent.

[xantithor]

Thank-you Ken. I initially was using the % in the formula, and it didn't work each attempt I made. I ended up convincing myself that % wasn't needed due to it didn't work. The simplicity of adding in + 1 into the formula never entered my mind.