Goals

• Define and use your first Java classes
• Understand how to compare floats

Task: Points and Distances

Point Class

Create a class, named Point to represent a point on the Cartesian plane. Study our own Point documentation.

Step 1: Instance variables

A point in the Cartesian plane has x and y coordinates, both of type double.

Step 2: Constructors

Provide two constructors:

• A constructor without parameters creates a Point at location (0.0, 0.0).
• A two-parameter constructor takes as input two double numbers corresponding to x and y, and constructs an object of type Point at location (x,y).

Step 3: toString()

As with any other class you write, define a toString() method to provide the means of printing the contents of the object in an informative and concise way.

Step 4: Getters and setters

Include appropriate getters and setters. Make sure to check the javadoc to see which getters and setters we expect.

Step 5: Instance methods

Define the following instance methods:

• findDistance(): an instance method that takes as parameter a Point. It computes and returns the distance between the current Point (also known as this) and the parameter, using the Pythagorean formula.

• areEquidistant(): an instance predicate method that takes as input two Point objects, and returns true iff (if and only if) the distances between the current (this) Point and each of the input points differ by less than some amount called TOLERANCE. Define TOLERANCE as a final variable with the value of 0.01.

• Include a main() method for testing purposes. Make sure to create at least three instances of type Point. Compute, and report if any of the points created is equidistant to the other two.

Notes and tips:

• Read the book section about comparing floating point values. It is recommended that you do not use "==". Tip: The TOLERANCE will be helpful here.
• The main method should be short and high level: It should consist primarily of calling other methods from the class.
• Make sure to test each method carefully before moving on to the next one.
• Choose your testing cases carefully to thoroughly test all the methods you defined. Print what you expect the test to produce and the result of your method call.
• When finished, save the printout of your main into a file named TestingPoint.txt. You will submit this file too.
• Make sure to read the javadoc provided carefully, to ensure your methods work as expected.

What to submit:

• Submit only your Point.java file and a TestingPoint.txt file that contains the results of your testing.
• We expect your code to have careful and meaningful documentation on every method and for the whole file. Also, do not forget to include the @author and @version fields in the file documentation. Without them, the graders will not grade your work.

Happy coding your first class!