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Simple blackjack java game  RSS feed

 
mike laww
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I am trying to code a simple blackjack game with no suits or anything. Just for number values 1-10 between the dealer and the player. I have it mostly coded out yet, for some reason, when I prompt the system to ask if you want to play again via (y/n).... I type in "y" to play again and it will say I won - just by typing in y to play again! Its frustrating and if anyone could point me in the right direction it would be greatly appreciated.

 
Junilu Lacar
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Hi Mike,

Welcome to the Ranch!

When posting code, please UseCodeTags (←click that link to learn how). They make code so much easier to read and reference in replies because they provide line numbers to the listing. As a courtesy to a newcomer such as yourself, we will add those for you this time.
 
Junilu Lacar
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A few things that led you to the place where you find yourself now: painted into a corner and wondering how the heck you're going to get out of it.

1. You put everything in your main() method. We have a wiki page that explains why Main Is A Pain. You might want to read that if you want to avoid feeling that pain over and over again.

2. Because you have put all your code into the same method, you have amassed a huge amount of it. Lots of code in one method is BAD. Lots of code that does lots of things in one method is WORSE. Lots of code that does lots of things in loops that have been nested lots of times is the WORST.  Wait for it...

3. Code that is not aligned properly to clearly show the different levels of logical structures of your code is the WORST of the WORST.

Ok, so there's a lot of bad stuff going on in that code and I've even barely scratched the surface.

So you don't feel too bad, let me just say that it's a pleasant surprise to see someone use something like "n".equals(anotherCard). There are a couple things right about that little gem in the muck around it but just look at it for a little bit if you want to feel better.

Next reply, we'll talk about what you can do to get out of that corner.
 
Junilu Lacar
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So, there are at least two ways you can try to get yourself out of this sticky situation you're in:

1. Hack your way out.

2. Clean your way out.

One way may get you out eventually but it's likely to leave your code in a bigger mess than it's in now.

The other way, of course, will get you out with your code in much better shape than what it's in now.

You choose. The right way is not always the easiest way though.
 
mike laww
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Thank you for the response, this is stressing me out to say the least. I'm gonna try to tidy it up to make it easier to understand and maybe that'll help with trying to figure out what exactly is going on with my code. I will definitely take a read at the wiki page that you linked as to avoid this pain over and over again .
 
Junilu Lacar
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Well, the first thing you want to do is reformat your code so that it's properly aligned. At least that will bump your code down from being the WORST of the WORST to just being the WORST.

In Eclipse or NetBeans, the keyboard command to autoformat your code is CTRL+SHIFT+F.  That will give you something like the listing below; I added some blank lines to get separation between a few logical parts of the code (another favor... you owe us TWO now):
 
mike laww
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Such a simple command to format my entire code, gee that would've been nice to know... professor. Ya think she would've taught us such a simple trick!
 
Junilu Lacar
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mike laww wrote:Such a simple command to format my entire code, gee that would've been nice to know... professor. Ya think she would've taught us such a simple trick!

Yeah, you'd think that would be one of the first things they teach but no. It's one of the first things I taught my son when he enrolled in his first programming course in college last year.

Have you made your choice on which way you want to go? Hack your way out or Clean your way out? Choose wisely... there is only one path down which I will be willing to go with you. Choose poorly and you're on your own.
 
mike laww
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I believe the best decision would be to clean my way out, as I for sure don't want to leave my code in a bigger mess than when it started.
 
Junilu Lacar
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Good deal. One more little detail to get out of the way. Have you been taught about using methods yet or is your teacher the one who's been telling you to jam everything and the kitchen sink into the main() method? Because you're going to have to create a bunch of smaller methods to separate, segregate, and compartmentalize all the different things that your program is doing right in that one main() method. That's the goal. Instead of having to cook, eat, shower, attend to bodily functions, sleep, study, exercise, and entertain in the same room of your house, i.e. your main() method, you're going to create a bunch of little "rooms" (called "methods") so that in each room, you can do one thing and only that one thing. So, however many "things" it is that you want to do, that's how many "rooms" you're going to create and that's where you're going to move all the clutter you have in main() out to. Does that make sense?
 
mike laww
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This is my first programming class for my major so sadly she hasn't really touched on methods. As much as you probably hate to hear it, she has just been having us cram everything into the main method so far, which after your description doesn't seem like the logical way to do it. I really like the idea of having separate methods as it would be so much easier to organize thoughts and not get lost in your own code. Your example made it very easy to understand the concept. So, would it be organized by different data types? Like a method for loops, method for if statements, method for setting and getting variables, etc?
 
fred rosenberger
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your methods should NOT be for loops or if statements.

methods should be broken out by actions as described in English (or whatever language you speak).  Imagine you were telling a story of what happens:

Deal a card to the player
Deal a card to the dealer
Deal a card to the player
Deal a card to the dealer
ask the player what they want to do
get their answer
etc..

you do this, then look for "actions".  So, "deal a card" is something you DO.  Note that it doesn't matter who you are dealing to, the process is the same - select a card from what's left in the deck.  once you know what it is, you add it to the correct player's hand...

Methods for getting and setting variables are OK - they're sometimes called "getters" and "setters", or "accessors" and "mutators" (I think), but they are part of a class (like a Player class). I'm not sure if you're going to start defining your own classes yet...
 
Junilu Lacar
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mike laww wrote:So, would it be organized by different data types? Like a method for loops, method for if statements, method for setting and getting variables, etc?

As Fred said, your program is broken out by actions. I like to call them "behaviors" because I find that helps shift your mindset to a place where it's more natural to think of the programs as living, sentient "things", i.e. Objects. You heard that Java is an object-oriented programming language, right?

Let's not get ahead of ourselves yet though. Just think of it for now as something called "functional decomposition" - breaking down your huge problem into smaller, more manageable problems that focus on one small part of the larger whole.
 
Junilu Lacar
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Also, think about it as a kind of layering and drilling down from high-level instructions to low-level detailed, step-by-step instructions.  It's kind of like how your mom might ask you to cook Thanksgiving dinner. That's "high-level" - you don't have a lot of details, just one command to do something. When you get home, you're like "Ok, I'm here, what do I do now?" and Mom will say, "Well, we want to prepare mashed potatoes, turkey, and bean casserole. Everybody else is bringing a different dish for dinner." So now you have a little more detail.

This gradual breaking down of the problem from high-level to more details, then to even more details as you drill down and finally arrive at the smallest task, like "Mom, how do I peel the potatoes?" and Mom will say, "Go to the drawer next to the sink, pull it out, dig around for the peeler, make sure you wash the potatoes first, then get a trash bag ready, walk over to the island, set the potatoes down, then start peeling those taters!"  That level of detail would not have been appropriate during that first time that she asked you to prepare Thanksgiving dinner, right? 

Mom held off giving you those details until just the right moment when you were ready to follow that many detailed instructions to a Tee. Giving you all of those detailed instructions up front would have been like the mess that you find right now in your main() method, right? All jumbled up and confusing as heck. How would you ever get dinner ready that way?!

That's kind of like how you want to layer your program instructions. Start with the large one-liner command in the main() method.  Ideally, it would look something like this:

That's it!  And then, the play method would look something like this:

And then you just keep drilling down into more details of each of the initPlayer(), initGame(), playUntilSomebodyWins(), and other methods you see there.

It's not that complicated. It just takes a little bit of organization and logical thinking.
 
It is sorta covered in the JavaRanch Style Guide.
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