Question

I’m trying to refresh my programming & UML after a summer break. Here’s an UMLdiagram I want to convert into Java code.

Here is my code so far, I’m not sure if its even close to being right.

public class Money {
public int money;
public int kronor, öre;
public Money(int kronor, int öre){
}

public int getKronor(){
    return kronor;
}

public int getÖre(){
    return öre;
}

public boolean isPositive(){
    return (money>0);
}

public boolean isNegative(){
    return (money<0);
}

public boolean isZero(){
    return (money==0);
}

public String toString(){

}

}

The biggest problem is that I’m not completely sure what these ?methods? mean/do.

+Money(in money : Money)
+Money(in kronor : int, in öre : int)
+add(in addend : Money) : Money
+subtract(in subtrahend : Money) : Money

It’s probably the “in” thing which I’m not sure about!

As a bonus, I would be grateful for any good link or if you could point out some examples of how to implement these methods.

Answer 1

+Money(in money : Money)

This is a constructor – it creates a new Money object with the same value as the Money object being passed in.

+Money(in kronor : int, in öre : int)

This is a constructor – it creates a Money object with the same values passed in (major unit and minor unit (kronor/öre, dollar/cent, pound/pence etc )

+add(in addend : Money) : Money

This method adds the Money object passed in as an argument to the method, to this Money object, and returns a new Money object that is the sum of the two. “Addend” means the object added to this object.

+subtract(in subtrahend : Money) : Money

Hopefully, by now, you can guess what this one does. “Subtrahend” means the object subtracted from this object.