Equality Comparison function

Suppose you want to compare two types of the Shape class. Since Shapes are custom classes, the compiler does not know how to compare two objects with different properties or which property to take into account. First, we need to decide what we need to compare in order to determine the equality of two Shape objects.

Let's assert that we declare two shapes equal whenever their areas are equal. We can do this by overriding the default equals method.

1public class Shape {
2    protected int maxWidth;
3    protected int maxHeight;
4
5    public double getArea() {
6        return getMaxArea();
7    }
8
9    @Override
10    public boolean equals(Object obj) {
11        if (obj == null)
12            return false;
13        if (obj == this)
14            return true;
15        System.out.println("Comparing");
16        return this.getArea() == ((Shape) obj).getArea();
17    }
18    // Other attributes and Methods
19}