Question

I’m pretty new to OOP, so any help is appreciated. I have a class file that takes some inputs and calculates the area of a triangle like such:

public class Triangle
{
    private int base;
    private int height;
    private double area;
    private String name;
    private double totalArea = 0;


    public void writeOutput()
    {
        System.out.println("Triangle name: " + name);
        System.out.println("Triangle base: " + base);
        System.out.println("Triangle height: " + height);
        System.out.println("Triangle area: " + setArea());
        System.out.println("Total Area: " + totalArea);
    }

    private double setArea()
    {
        area = (base * height) * 0.5;
        return area;
    }

    private double setTotalArea()
    {
        totalArea += area;
        return totalArea;
    }
}

My problem is in the setTotalArea() method. Basically, it is supposed to add up a cumulative total of all the areas calculated, however, all it is doing is echoing the area and I can’t figure out why. Any suggestions are appreciated!

Answer 1

You’re mixing up setters and getters. For instance, your setArea() method is not a true “setter” method as it is private, accepts no parameter, sets nothing, and tries to return a value — the exact opposite of most things a setter should do, and the same goes for your setTotalArea.

Anyway, sorry to say, but this code is borked, and I recommend you simply get rid of it and start over (it’s not that big of a class yet, so this is no big deal), but start with your fields (height, base, and name), the constructor, perhaps one that sets class properties and with true public setter methods that actually accept parameters and use those parameters to set class fields. Then create your getter methods that return the values of the class fields. Your class shouldn’t even have a setArea method or an area field since the area is a calculated value, not a set value, ant it should probably be calculated on the spot in the getArea() method and returned.

Edit, you state:

My problem is in the setTotalArea() method. Basically, it is supposed to add up a cumulative total of all the areas calculated, however, all it is doing is echoing the area and I can’t figure out why. Any suggestions are appreciated!

Sorry, but I don’t understand this. total of what areas? The class only describes one triangle and so there is no cumulative area concept here. Now if you have another class that holds an array or collection of Triangle objects, then a *get*TotalArea (not set total area) method would make sense as it would add the areas of all triangles in the collection, but you don’t have this here.