Let us assume you are writing the Rectangle class in Java:

public class Rectangle { private final double cornerX; private final double cornerY; private final double width; private final double height;

public Rectangle(double cornerX, double cornerY, double width, double height) { this.cornerX = cornerX; this.cornerY = cornerY; this.width = width; this.height = height; }

/** Outputs a rectangle as a string * The string is [cornerX, cornerY, width, height] * */ public String toString() { String s = "[" + cornerX + "," + cornerY + "," + width + "," + height + "]"; return s; } }

You want to plan ahead, so that others can use Rectangle. You consider that someone may create an instance of Rectangle as follows: Rectangle r = new Rectangle(10, 5, 15, 7); You now consider that they may wish to find the width of r. What is the best thing you can do to your code to allow this?

1:

You should add a public method called getWidth()

2:

Nothing needs to be done. They should simply use r.width

3:

You should make width a public variable.

4:

Nothing. The variable is private because no one should need to know what its value is.