HELLO Im New Here! ..and having problems about this ..I am doing #2 which requires #1. And im done with my code. and i have this little confuse about the Cylinder class here's the question :
Im confuse about this because of Polymorphism.. I miss the lecture because im late..but im doing a self study but about this problem i cant understand and do the coding.. but i have already done in inheritance the questions & coding of 1 and 2.. here is my code for #13. Every cylinder has a base and height, where the base is a circle. Design the class CYLINDER that can capture the properties of a cylinder and perform the usual operations on a cylinder. Derive this from the class CIRCLE designed in No.2. Some operations that can be performed by the cylinder are as follows: calculate and print the volume, calculate and print the surface area, set the height, set the radius of the base, and set the center of the base.
This is for Point.java
class Point { // Declare variables private double x; private double y; // Empty constructor public Point() { } // Constructor with variables public Point(double x, double y) { this.x = x; this.y = y; } // Used to set the new x-coordinate public void setX(double x) { this.x = x; } // Used to set the new y-coordinate public void setY(double y) { this.y = y; } // Used to display the x-coordinate public double getX() { return x; } // Used to display the y-coordinate public double getY() { return y; } }
This is for the Circle.java which extends Point.java
import java.lang.*; public class Circle extends Point { // Declare variables private double r; // Empty constructor public Circle() { } // Constructor with variables public Circle(double x, double y, double r) { super(x, y); this.r = r; } // Used to set the radius public void setR(double r) { this.r = r; } // Used to return the radius public double getR() { return r; } // Calculates the area public double area() { return Math.PI*r*r; } // Calculates the circumference public double circumference() { return 2*Math.PI*r; } }
And Ive created a class to test my Code which i named Tester.java
import java.util.*; public class Tester { static Scanner console = new Scanner(System.in); public static void main(String[] args) { // Declare variables int loopDecision, xC, yC, rC; // Loop statement System.out.println("Enter 1 to insert your own values. " + "Enter 2 to use preset values."); loopDecision = console.nextInt(); /* If 1 is chosen then it goes into the if loop. * In the if loop the user will be able to set their * own coordinates and radius. They will then get the * area of the circle and the circumference. */ if(loopDecision == 1) { // Ask user to input values System.out.println("Enter a number 1-10 for the X coordinate."); xC = console.nextInt(); System.out.println("Enter a number 1-10 for the Y coordinate."); yC = console.nextInt(); System.out.println("Enter the radius."); rC = console.nextInt(); System.out.println(); // Set the Circle class. Circle p = new Circle(xC, yC, rC); // Display their entered values System.out.println("X coordinate = " + p.getX()); System.out.println("Y coordinate = " + p.getY()); System.out.println(); // These two for loops display the values on the side and bottom for(int i = 10; i > 0; i--) { System.out.println(i); } for(int i = 1; i <= 10; i++) { System.out.print(" " + i); } System.out.println(); System.out.println("Radius = " + p.getR()); // Display the area and circle System.out.println("Area of the circle = " + p.area()); System.out.println("Circumference of the circle = " + p.circumference()); } /* In the else loop the user will be able to see * the varius functions of the program. Using preset * values assigned by me. */ else { // Set the values Circle p = new Circle(10, 3, 5); System.out.println(); // Display the starting values System.out.println("Initial x-coordinate = " + p.getX()); System.out.println("Initial y-coordinate = " + p.getY()); System.out.println(); // These two for loops display the values on the side and bottom for(int i = 10; i > 0; i--) { System.out.println(i); } for(int i = 1; i <= 10; i++) { System.out.print(" " + i); } System.out.println(); System.out.println("Initial radius = " + p.getR()); System.out.println(); System.out.println("Now changing the values."); System.out.println(); // Set new values p.setX(5); p.setY(10); p.setR(4); // Display the new values System.out.println("X coordinate = " + p.getX()); System.out.println("Y coordinate = " + p.getY()); System.out.println(); // These two for loops display the values on the side and bottom for(int i = 10; i > 0; i--) { System.out.println(i); } for(int i = 1; i <= 10; i++) { System.out.print(" " + i); } System.out.println(); System.out.println(); System.out.println("Radius = " + p.getR()); // Show area and circumference with the new values System.out.println("Area of the circle = " + p.area()); System.out.println("Circumference of the circle = " + p.circumference()); } } }
Any help i appreciated about this.. thank you..
And can you re-check my code if it is correct?..