void_Anthony() has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to get a random number and assign it to a variable (may seem stupid, but I'm still having trouble.) The code I'm having a problem with: 
do{
  $goblin=$goblin-$damage;
  if($goblin<0){
  $goblin=0;
  }if($wizard<0){
  $wizard=0;
  }
  if($room==6){
   my  $dmg=int (rand 5)+1;
  }elsif($room==3){
   my  $dmg=int (rand 4)+1;
  }elsif($room==2){
   my  $dmg=int (rand 3)+1;
  }elsif($room==1){
   my  $dmg=int (rand 2)+1;
  }
  $wizard-=$dmg;
  print "wizard health: $wizard\t";
  print "$monster health: $goblin\n";
 }until($goblin<=0 || $wizard<=0);
  if($wizard>0){
   print "good job you got $newgold gold!\n";
   $gold+=$newgold;
   &freedale;
  }elsif($wizard<=0){
  &die;
}
    }else{
      print "Please enter 1, 2, or q...\n";
      &battle;
        }

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I'm trying to get a random value for $dmg (depending on the room you're in) and then subtract that from $wizard. Unfortunately, every time i run the program, $wizard doesn't change (originally 50.) If someone could offer some advice as to what I'm doing wrong, I would appreciate it.

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Re: Random Numbers?
by dragonchild (Archbishop) on May 10, 2005 at 19:50 UTC
    Add the following to the top of your script. 
    use strict;
use warnings;

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    The problem will be self-evident.

    For those who can't wait ...

    Read more... (174 Bytes)
    • In general, if you think something isn't in Perl, try it out, because it usually is. :-)
    • "What is the sound of Perl? Is it not the sound of a wall that people have stopped banging their heads against?"
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Re: Random Numbers?
by Forsaken (Friar) on May 10, 2005 at 21:07 UTC
    Completely off-topic, but have you ever considered using spaces in your code? Especially when things get more complicated I personally tend to find $wizard -= 1 a lot easier to read than $wizard-=1. Same thing for the if conditions tbqh, if($x == 1) seems easier to read than if($x==1). Perhaps tis just a matter of taste, don't know how others feel about it.

    update(suggested by Animator ;-)
    You might want to take a look at the Perlstyle POD for some very good insights on the subject.

    Remember rule one...

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Re: Random Numbers?
by polettix (Vicar) on May 10, 2005 at 23:08 UTC
    The topic has been discussed in depth but I'd like to share a couple of notes.

    Follow Forsaken's advice about formatting. You can also find the perltidy program quite useful, it should be in the basic distribution and basically does the work. I was particularly curious about the following lines: 

      if($goblin<0){
  $goblin=0;
  }if($wizard<0){
  $wizard=0;
  }

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    The second if comes immediately after the closing block associated to the previous one, which makes it less readable - it may be taken for an elsif at first glance.

    Another consideration deals with the way you eval the damage with the if/elsif/... checks. I'd rather use some kind of data structure here: 

    # Early in the code, i.e. in some configuration section
my @max_damages = (0) x $number_of_rooms;
@max_damages[ 1, 2, 3, 6 ] = ( 2, 3, 4, 5 );

# ... then
$wizard -= 1 + int(rand($max_damages[$room]));

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    This should save you the bore to add new elsif branches when you add rooms.

    One final question: what does it happen in rooms 4 and 5? Or is the test for room "6" just a typo, and you meant "4"? If so, note that there's even a simpler solution using rooms as numbers: 

       $wizard -= 1 + int(rand($room + 1));

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    Flavio (perl -e 'print(scalar(reverse("\nti.xittelop\@oivalf")))')

    Don't fool yourself.
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Re: Random Numbers?
by trammell (Priest) on May 10, 2005 at 20:09 UTC 
    }elsif($wizard<=0){
    &die;
}

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    You might want to use a different function name, since die() is already a Perl builtin. Unless you really meant to call Perl's die().

    You also have $dmg and $damage variables. Are they supposed to be different?

    Update: Thanks, [id://Animator]. Spending time here in PM is great for clearing up my little "pockets of ignorance".

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      You cannot prefix a perl-built-in function with an ampersand. All functions prefixed by an ampersand are user-defined functions... which means he isn't calling Perl's die()
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Re: Random Numbers?
by dynamo (Chaplain) on May 10, 2005 at 21:28 UTC
    Sorry for the off-topic but I just wanted to say it's really cool looking at code with variable names like $wizard and $goblin, and dealing with algorithms to do combat resolution in a fantasy RPG type setting..

    I wrote a lot of that kind of stuff when learning to program. Please feel invited to post more along these lines.

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      You'll find more (and various version of this code) at Wizardv1.1... Hey, please join us if you wish :)
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Re: Random Numbers?
by DrHyde (Prior) on May 11, 2005 at 09:27 UTC
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