Implementing an Interface

# The Procedure

## Real Lab Procedure

• First, click on the class diagram then the below diagrams will be shown.
• There are two classes in the program, and it has three parts [class name, variables, function].

Fig 1

Fig 2

• Fig 1 shows the class diagram of class Point.
• Fig 2 shows the class diagram of class Driver.
• Then click on the sequence diagram which will show how the program that on the left side is executed.

Sequence diagram

Following steps are explaining sequence diagram.

• The diagram defines a class called Point with two private instance variables: x and y, which represent the coordinates of a point in a 2D plane.
• The Point class has four private methods.
• setX(int xCoord) sets the value of the x coordinate.
• setY(int yCoord) sets the value of the y coordinate.
• getX() returns the value of the x coordinate.
• getY() returns the value of the y coordinate.
• Next, an interface named Shape is defined. It includes the following.
• A public static final constant pi with a value of 3.14.
• Two abstract methods: area() and perimeter(), which any class implementing this interface must provide concrete implementations for.
• The code then defines a class named Circle which implements the Shape interface.
• The Circle class has a protected instance variable radius to store the radius of the circle.
• The constructor Circle(double r) initializes the radius with the given value r.
• The area() method calculates and returns the area of the circle using the formula: pi * radius * radius.
• The perimeter() method is not defined properly in the code. It seems like there's a typo with the variable p, and it's missing a return statement. It should be fixed to properly calculate and return the perimeter of the circle using the formula: 2 * pi * radius.
• Inside the main method, an instance of the Circle class is created with a radius of 5.
• The area() method of the Circle class is called to calculate the area of the circle.
• The perimeter() method of the Circle class is called to calculate the perimeter of the circle.
• The results are then printed to the console using System.out.println().

# Simulator Procedure

• There are two buttons [Class Diagram and Sequence Diagram] on the right side of the simulation.
• First, click on the Class Diagram then the class diagrams will be shown.
• Then click on the Sequence Diagram, it will display two buttons – Previous and Next.
• The Next button shows the next sequence, and the Previous button shows the previous sequence.
• After all the sequence diagrams the result box will be shown.
• Click on the Reset button to redo the simulation.