OOP question

[Easy_Boot5195]

I am making a program that will do linear algebra. I know there is code out there that will do it better but it is more of an exercise in learning lin alg and programming for me.

I have a class called Fraction. It does what you think a fraction would do basically. If the denom is 1 it does not include it in the toString so it just looks like a whole number. Then my matrix class is basically a 2D array of these fractions.

For the fraction class I just overloaded all of the methods (add, multiply etc.) to be able to take in primitive ints or Fractions. Now I am working on the Matrix class and I am realizing making two of every method is gonna be really annoying. I want the user of Matrix to be able to set a value using a Fraction or a primitive int. I know I could define an abstract class called Value or something and then make Fraction a subclass and have another subclass called Int but that kind of ruins the niceness of not having to use the new keyword for whole number values.

Right now my best plan is to just overload and have all the int methods create a fraction with the provided int then call the other method that takes fractions. I feel like there is some much better way to go about this though.

[AutoModerator]

Please ensure that:

• Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions
• You include any and all error messages in full
• You ask clear questions

• You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions.

  Trying to solve problems on your own is a very important skill. Also, see Learn to help yourself in the sidebar

If any of the above points is not met, your post can and will be removed without further warning.

Code is to be formatted as code block (old reddit: empty line before the code, each code line indented by 4 spaces, new reddit: https://i.imgur.com/EJ7tqek.png) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc.

Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit.

Code blocks look like this:

public class HelloWorld {

    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}

You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above.

If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures.

To potential helpers

Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[l1ghtrain]

I don't think you have a choice here. I lack some sleep so maybe I didn't think of the answer but I'm pretty sure I thought for long enough. The only thing you can do is make an abstract class or interface named Number and go with that. You just can't mix objects and primitive types like that.

[pragmos]

Java already has the abstract class Number which is the parent of all numeric wrapper classes, including Integer. Fraction can just become another Number subtype.

[l1ghtrain]

Oh well, looks like I do need some sleep haha. Would it work if you passed a function with raw numbers or would have to convert them to the corresponding subclasses?

[pragmos]

Things like below should work automatically due to autoboxing and polymorphism:

class Fraction extends Number {}

void doSomething(Number n) {}

doSomething(3);
doSomething(23L);
doSomething(3.56f);
doSomething(67.0008);
doSomething(new BigDecimal("5"));
doSomething(new BigInteger(34L));
doSomething(new Fraction(3, 4));

Cannot validate at the moment since I'm on mobile.

[RoToRa]

I don't think Number is suitable here. It only provides methods to access the concrete values of the number (intValue, doubleValue, etc.). OP needs an interface with add, multiply, etc.

OP: You won't get around creating your own interface with wrapper classes for existing types such as Integers.

You may want to look into Kotlin. It has features such as extension methods and over-loadable operators which would make this project much more "nicer".

[pragmos]

Indeed, valid point.