LAB 4

ex1


public class Circle {
    private double radius;
    private String color;

    public Circle() {
        this.radius = 1.0;
        this.color = "red";
    }

    Circle(double r) {
        radius = r;
        color = "pink";
    }

    Circle(double r, String c) {
        radius = r;
        color = c;
    }

    public double getRadius() {

        return radius;
    }

    public double getArea() {
        return 2 * Math.PI * radius;
    }
}


public class TestCircle {
    public static void main(String[] args) {
        Circle c1 = new Circle();
        System.out.println("The first circle has the length of the radius: " + c1.getRadius());
        Circle c2 = new Circle();
        System.out.println("The second circle has the area: " + c2.getArea());
    }
}


ex3

public class Author {
    private String name;
    private String email;
    private char gender;

    public Author(String name, String email, char gender) {
        this.name = name;
        this.email = email;
        this.gender = gender;
    }

    public String getName() {

        return name;
    }

    public String getEmail() {

        return email;
    }

    public char getGender() {

        return gender;
    }

    public void setEmail(String email)
    {
        this.email = email;
    }

    public String toString() {
        String v = this.name + "(" + this.gender + ") at " + this.email;
        return v;
    }
}


public class TestAuthor {
    public static void main(String[] args) {
        Author a1 = new Author("Ana Popescu", "anapopescu@yahoo.com", 'f');
        Author a2 = new Author("Alexandru Rus", "alexandru.rus@yahoo.com",'m');
        Author a3 = new Author("Maria Campean", "mariacampean12@yahoo.com", 'f');
        System.out.println("The name of the first author is "+ a1.getName());
        System.out.println("The gender of the second author is "+ a2.getGender());
        System.out.println("The email of the third author is "+ a3.getEmail());
        String s = a1.toString();
        System.out.println("First author: "+s);
        a2.setEmail("alexandru_rus@gmail.com");
        System.out.println("The new email of the second author is "+a2.getEmail());
    }
}


ex3

public class Book {
    private String name;
    private Author author;
    private double price;
    private int qtyInStock;

    public Book(String name, Author author, double price) {
        this.name = name;
        this.author = author;
        this.price = price;
    }

    public Book(String name, Author author, double price, int qtyInStock) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.qtyInStock = qtyInStock;
    }

    public String getName() {
        return name;
    }

    public Author getAuthor() {
        return author;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public int getQtyInStock() {
        return qtyInStock;
    }

    public void setQtyInStock(int qtyInStock) {
        this.qtyInStock = qtyInStock;
    }

    @Override
    public String toString() {
        String v = this.getName() + " by " + this.author.toString();
        return v;
    }
}


public class TestBook {
    public static void main(String[] args) {
        Author a1 = new Author("Anna Todd", "annatodd@yahoo.com", 'f');
        Author a2 = new Author("Suzzane Collins", "suzzanecollins@yahoo.com", 'f');
        Author a3 = new Author("Veronica Roth", "veronicaroth@yahoo.com", 'f');
        Book b1 = new Book("After", a1, 25, 150);
        Book b2 = new Book("Hunger Games", a2, 15, 110);
        Book b3 = new Book("Divergent", a3, 20, 200);
        System.out.println("The author of the book After is " + b1.getAuthor());
        System.out.println("The second book is " + b2.getName());
        System.out.println("The price of the third book is " + b3.getPrice() + " dollars");
        System.out.println("There are " + b1.getQtyInStock() + " After books in stock");
        b2.setPrice(13);
        System.out.println("The new price of the Hunger Games book is " + b2.getPrice() + " dollars");
        b3.setQtyInStock(90);
        System.out.println("There are only " + b3.getQtyInStock() + " Divergent books in stock! Don't miss your chance to buy one!");
        System.out.println("The information about the third book is " + b3.toString());
    }
}


ex4

public class Book {
    private String name;
    private Author[] authors;
    private double price;
    private int qtyInStock = 0;

    public Book(String name, Author[] authors, double price) {
        this.name = name;
        this.authors = authors;
        this.price = price;
    }

    public Book(String name, Author[] authors, double price, int qtyInStock) {
        this.name = name;
        this.authors = authors;
        this.price = price;
        this.qtyInStock = qtyInStock;
    }

    public String getName() {

        return name;
    }

    public Author[] getAuthors() {
        return authors;
    }

    public double getPrice() {

        return price;
    }

    public void setPrice(double price)
    {
        this.price = price;
    }

    public int getQtyInStock() {

        return qtyInStock;
    }

    public void setQtyInStock(int qtyInStock) {
        this.qtyInStock = qtyInStock;
    }

    @Override
    public String toString() {
        String v = this.getName() + " by " + authors.length + " authors ";
        return v;
    }

    public void printAuthors() {
        int i;
        for (i = 0; i<=authors.length; i++){
            System.out.println(this.authors[i].toString());
        }
    }
}


public class TestBook {
    public static void main(String[] args) {
        Author a1 = new Author("John Green", "johngreen@gmail.com", 'm');
        Author a2 = new Author("Maureen Johnson", "maureenjohnson@gmail.com", 'f');
        Author a3 = new Author("Lauren Myracle", "laurenmyracle@gmail.com", 'f');
        Author a4 = new Author("Stephanie Dray", "stephaniedray@yahoo.com", 'f');
        Author a5 = new Author("Vicky Alvear", "vickyalvear@yahoo.com", 'm');
        Author[] authors = new Author[3];
        authors[0] = a1;
        authors[1] = a2;
        authors[2] = a3;
        Book b1 = new Book("Let it snow", authors, 30);
        authors = new Author[2];
        authors[0] = a4;
        authors[1] = a5;
        Book b2 = new Book("A day of fire", authors, 26, 100);
        System.out.println("The second book is " + b2.getName());
        System.out.println("Authors: ");
        b2.printAuthors();
        System.out.println("The price of the first book is " + b1.getPrice() + " dollars");
        System.out.println("There are " + b1.getQtyInStock() + " Let it snow books in stock");
        b2.setPrice(13);
        System.out.println("The new price of the second book is " + b2.getPrice() + " dollars");
        b2.setQtyInStock(90);
        System.out.println("There are only " + b2.getQtyInStock() + " A day of fire books in stock!");
        System.out.println("The information about the first book:", b1.toString());
    }
}



ex5


    public class Cylinder extends Circle {
        private double height;
        private double volume;

        public Cylinder() {
            this.height = 1.0;
        }

        public Cylinder(double radius) {
            super(radius);
        }

        public Cylinder(double radius, double height) {
            super(radius);
            this.height = height;
        }

        public double getHeight() {
            return this.height;
        }

        @Override
        public double getArea() {
            double a=this.getRadius() * this.getRadius() * 3.14 * this.height;
            return a;
        }
    }


public class TestCylinder {
    public static void main(String args[]) {
        Cylinder c1 = new Cylinder(2, 8);
        Cylinder c2 = new Cylinder(1, 5);
        Cylinder c3 = new Cylinder(4, 2);
        System.out.println("Area of c1 = " + c1.getArea());
        System.out.println("Area of c2 = " + c2.getArea());
        System.out.println("Area of c3 = " + c3.getArea());
    }
}
}



ex 6

public class Circle extends Shape {
    private double radius;

    public Circle() {
        this.radius = 1.0;
    }
    public Circle(double radius){
        this.radius = radius;
    }
    public Circle(double radius, String color, boolean filled){
        super(color,filled);
        this.radius = radius;
    }

    public double getRadius() {
        return radius;
    }

    public void setRadius(double radius) {
        this.radius = radius;
    }
    public double getArea(){
        return this.radius*this.radius*3.14;
    }
    public double getPerimeter(){
        return 2*3.14*this.radius;
    }
    @Override
    public String toString(){
        return "A Circle with radius "+this.radius+" which is a subclass of "+ super.toString();
    }
}




public class Rectangle extends Shape {
    private double width;
    private double length;

    public Rectangle() {
        this.width = 1.0;
        this.length = 1.0;
    }

    public Rectangle(double width, double length) {
        this.width = width;
        this.length = length;
    }

    public Rectangle(double width, double lenght, String color, boolean filled) {
        super(color, filled);
        this.width = width;
        this.length = lenght;
    }

    public double getWidth() {
        return width;
    }

    public void setWidth(double width) {
        this.width = width;
    }

    public double getLength() {
        return length;
    }

    public void setLength(double length) {
        this.length = length;
    }

    public double getArea() {
        return this.width * this.length;
    }

    public double getPerimeter() {
        return 2 * (this.width + this.length);
    }

    @Override
    public String toString() {
        return "Rectangle with width= " + this.width + " and length= " + this.length + " which is a subclass of " + super.toString();
    }
}



public class Shape {
    private String color;
    private boolean filled;

    public Shape() {
        this.color = "red";
        this.filled = true;
    }

    public Shape(String color, boolean filled) {
        this.color = color;
        this.filled = filled;
    }

    public String getColor() {
        return color;
    }

    public void setColor(String color) {
        this.color = color;
    }

    public boolean isFilled() {
        return this.filled;
    }

    public void setFilled(boolean filled) {
        this.filled = filled;
    }

    @Override
    public String toString() {
        String s;
        if (filled = true)
            s = "filled";
        else s = "not filled";
        return "Shape{" + "color:" + color + ", is " + s + "}";
    }
}




public class Square extends Rectangle {

    public Square() {
    }

    public Square(double side) {
        super(side, side);
        side = side;
    }

    public Square(double side, String color, boolean filled) {
        super(side, side, color, filled);
        side = side;
    }

    public double getSide() {
        return super.getLength();
    }

    public void setSide(double side) {
        this.setLenght(side);
        this.setWidth(side);
    }

    public void setWidth(double side) {
        super.setWidth(side);
    }

    public void setLenght(double side) {
        super.setLength(side);
    }

    public String toString() {
        return "A square with side = " + this.getSide() + "which is a subclass of " + super.toString();
    }
}



public class TestShape {
    public static void main(String[] args) {
        Shape s = new Shape("green",true);
        System.out.println(s.toString());

        Circle c = new Circle(3,"yellow",true);
        System.out.println(c.toString());
        System.out.println("Area = "+c.getArea());
        System.out.println("Perimeter = "+c.getPerimeter());
        System.out.println("Is filled = "+c.isFilled());

        Rectangle r = new Rectangle(4,6,"pink",false);
        System.out.println(r.toString());
        System.out.println("Width = "+r.getWidth());
        r.setWidth(5);
        System.out.println("New width = "+r.getWidth());
        System.out.println("Area = "+r.getArea());
        System.out.println("Is filled = "+r.isFilled());

        Square sq = new Square(10,"turquoise",false);
        sq.setSide(3);
        System.out.println(sq.toString());
        System.out.println("Is filled = "+sq.isFilled());
        System.out.println("Perimeter = "+sq.getPerimeter());


    }
}