Code Guessing Game Review

[fast summit]

Hi All,

I am teaching myself Java and this is my first project. I was hoping someone could review it and give me any tips!

The game is based in the terminal. You have to guess a 4 digit code, the code is 4 different numbers (no repeats) and when you input a guess it will tell you how many correct positions and correct numbers you have. When you get the correct code the program stops.

Here is the code: https://github.com/jacoboneill/learning-programming/tree/main/practice-projects/code-guessing-game-java

Please either reply to this post or put it in the issues part of the repository

• Jacob

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[stark abyss]

• Nice separation of concerns

• Class names could probably be way better though

• The generated code's digits order is more arbitrary than random. Consider using a LinkedHashSet instead so that the digits come out in the same order as they were added, thus keeping the original random order

• avoid constantly referencing this. this.code here, this.code there, whose else's code would that be? Just write code. Coming from Python?

[coarse quarry]

(or js)

[stark abyss]

• consider proper rejection of invalid user input. That's one typical way to have vulnerabilities

[coarse quarry]

• you aren't using formatting to its full potential here https://github.com/jacoboneill/learning-programming/blob/main/practice-projects/code-guessing-game-java/src/Draw.java#L16, this would make it hard to localize (which is probably out of scope of your project, but it's practice in future-proofing)

[exotic epoch]

        this.entries.add(String.format(" %s |    %s    |     %s", guess.get("guess"), guess.get("correct"),

[coarse quarry]

flushing the output stream in the same class there is probably also unnecessary?

this part here is a questionable use of formatting. this class as a whole seems quite unnecessary, unless you were to also validate the content as kyo mentioned https://github.com/jacoboneill/learning-programming/blob/main/practice-projects/code-guessing-game-java/src/Guess.java#L5

[exotic epoch]

        return String.format("%-4s", input).replace(' ', '0').substring(0, 4);

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[fast summit]

How would you name the class names?

[fast summit]

I think more research needs to be done on my end. I've only used sets in python once or twice and never encoutered LinkedHashSets (I've heard of Linked Lists but idk what they are)

[stark abyss]

Something that would be like GameState, Display, and UserInput

[fast summit]

I come from JavaScript however this is my first attempting to do OOP instead of FP. When should you use this and when shouldn't you?

[stark abyss]

For information, a LinkedHashSet is like a HashSet but it enumerates entries in the order they were inserted

[fast summit]

I tried to figure out a way to use the scanner to limit to 4 digits or not allow the input to go through if theres less but there was nothing easy I could find

[stark abyss]

You should do your best not to need this. Afterwards, use this when it is necessary. Omit it when there is no reason to put it. In addition, it is normal to use this in constructors and in setters because the parameters shall be named the same as the properties.

[fast summit]

Could you explain what you mean by localize? Just interested in what you mean

[stark abyss]

Don't delegate to Scanner. Do it yourself

[fast summit]

The original intention was to just generate the code in the Code class and do validation in the Guess class however I thought passing the actual code between classes would defeat the purpose of it being secret (very silly thinking about it now)

[coarse quarry]

localization is the process of transforming content of something to be appropriate for a culturally different audience, it can involve translating text and speech, modifying assets to match cultural ideas, or replacing content like jokes for appropriate counterparts

[fast summit]

Ah Okay, Thank you @stark abyss

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[fast summit]

What order does a normal HashSet enumerate enteries? does it do a sort at the beginning?

[stark abyss]

Arbitrarily, as it suits it

[fast summit]

So only use the this keyword in the constructors?

[fast summit]

What does this mean? How else would I get the user input?

[stark abyss]

And setters. And sometimes you'll need it, you'll see it then

[fast summit]

Ah I understand. Good point, how would you go about solving the problem?

[stark abyss]

I didn't set get, I said reject. You get user input with Scanner, and you reject invalid input when it's invalid

[fast summit]

Ah okay, Thank you

[coarse quarry]

you could just utilize the formatting more, you can justify text with formatting itself already

[fast summit]

Okay, So just reset the screen if the input is invalid and add a comment underneath?

[fast summit]

Okay, I'll do more research into this and try to implement it next time

[stark abyss]

A remark that the input is invalid and asking for a new guess would be enough. The important part is to not pass around invalid input to the rest of your processing.

[fast summit]

All the suggestions have been great. Does anyone have any ideas for terminal like games I can do like this to try and implement this and learn more about Java?

[fast summit]

So the GameState class would be like doing validation and input?

[coarse quarry]

in increasing order of difficulty, hangman, checkers, battleship, chess, scrabble
seem like pretty promising games for a terminal context

[fast summit]

I love the idea of chess but I think I should try the hangman one first 😅

[coarse quarry]

i think mastermind is still easier than hangman so that seems like a reasonable next step

conway's game of life is probably really shit in terms of UI/UX for only text input and no GUI though so i'll retract that

[stark abyss]

No, validation should probably more or less be done by the input logic. Possibly with another class in charge of checking if input is valid. GameState is for knowing what's the true code and computing responses to guesses

[fast summit]

I've seen terminal based versions of conways game of life. The only issue is (as far as I know) there is no cross-platform way to get the terminal's height and width therefore making a grid and using 2D arrays is annoying becuase depending on the size it can move to the next line and look rubbish. Unless you know a way of getting around this

[fast summit]

Wouldn't computing responses to guesses be validation?

[coarse quarry]

you could target some platform or environment specifically to avoid the whole "cross-platform" issue tbh

[stark abyss]

No, I'm not sure what to call it, but not validation. More like abstract response

[coarse quarry]

my implementation just used a fixed size grid that updated every so often

it's bad for UX for drawing cells though

[fast summit]

I think I would just not draw a grid and use a monospace font on the terminal (which i think it already is) to still get the patterns. Debugging might be a pain though because of this.

[coarse quarry]

default fonts are monospace but not full-width, meaning they aren't squares

[fast summit]

Ah bugger. That throws a spanner in the works

[coarse quarry]

anyways that's not exactly what i mean, i mean when you initialize the board with alive/dead cells, that's going to be a pain without a GUI

[coarse quarry]

well not fully, they're half-width so theoretically 2 chars makes a full square, but i don't know how much that can be trusted

[fast summit]

You could use (U+2588) █ twice to get a full block but there's no way to make an empty block that is two characters wide

[coarse quarry]

uh, 2 spaces

[fast summit]

No I was thinking of something that would look like [] but the full height and width

but spaces should also work @coarse quarry

[fast summit]

Anyway I'm going to go make hangman. @stark abyss @coarse quarry Thank you for your help 🙂

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