Question

Question set 1 (Java) object oriented:

1.Write a class called Student. The class should be able to store information regarding the name, age, gpa, and phone number of a Student object. Please write all the setter and getter methods. Finally, write a Demo class to demonstrate the use of the class by creating two different objects.

2.Use the same Student class from the previous problem. This time,you will write a different Demo class, in which you will create three Student objects. You will store these three objects in a Student array that can hold up to 10 Student objects. Write another method in the Demo class called show Students(). This method, when called from the main method, will show all the student information, one object at a time, in the array on the console.

3.Write a class called Cat. The class should have two variables to store data regarding the name (String type) and weight (double type) of each Cat object. All cat objects will have a weight of 15 ounces when born (upon creation). Write the getter and setter methods. In addition, write a method called feed(int foodAmount). The feed method will allow the user to enter the amount of food fed to the cat object. The weight of the cat will increase by 1 ounce for 10 ounces of food is fed to the cat.Now write a Demo class, in which you will create a Cat object. Give the cat a name and feed the cat 5 times by calling the feed method five times in a row. Each time the food amount fed is a random integer number between 5 to 15 ounces. Display the name and final weight in pounds and ounces of the cat.

4.Write a Book class that contains book title and book price information. Write a Demo class in which you will create 1000 books. Each book title is made of a String composed of 5 to 10 random uppercase letters. Each book price is made of a random double value ranging from 0.00 to 99.99. Print these books in a nice formatted table of three columns on the console. The first column contains serial numbers from 1 to 1000. The second column contains book titles, and the third column contains their matching book prices with two decimal places.

Answer 1

Answer 1) //Basic Student Class along with getters and setters which will store the name, age, gpa, and phone number of a Student object

public class Student {
  
//declaration of variables
   private String name;
   private int age;
   private float gpa;
   private long phoneNumber;
     

//Getters and setters
   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   public int getAge() {
       return age;
   }

   public void setAge(int age) {
       this.age = age;
   }

   public float getGpa() {
       return gpa;
   }
   public void setGpa(float gpa) {
       this.gpa = gpa;
   }

   public double getPhoneNumber() {
       return phoneNumber;
   }

   public void setPhoneNumber(long phoneNumber) {
       this.phoneNumber = phoneNumber;
   }

//Constructor

public Student() {
   }

}

//Demo class to demonstrate two different objects for class Student

public class Demo {
  
   public static void main(String[] args) {
      
       //s1 is the first object of class Student
       Student s1 = new Student();
       s1.setName("Student 1");
       s1.setAge(20);
       s1.setGpa(9);
       s1.setPhoneNumber(9876543210l);
      
       //s2 is the second object of class Student
       Student s2 = new Student();
       s2.setName("Student 2");
       s2.setAge(22);
       s2.setGpa(9);
       s2.setPhoneNumber(9875643210l);
  
   }
}

Answer 2) Using the same Student class from the previous problem
I have created 3 different objevts s1, s2 and s3 in another Demo class

public class Demo {
  
   public static void main(String[] args) {
       showStudents();  
       //This method will display details all the student information, one object at a time
//I am demonstarting with object s1
   }

   private static void showStudents() {

       //studentArray will upto 10 Student objects
       Student[] studentArray = new Student[10];
      
           //s1 is the first object of class Student
           Student s1 = new Student();
           s1.setName("Student 1");
           s1.setAge(20);
           s1.setGpa(9);
           s1.setPhoneNumber(9876543210l);
           studentArray[0]=s1;
          
           //s2 is the second object of class Student
           Student s2 = new Student();
           s2.setName("Student 2");
           s2.setAge(22);
           s2.setGpa(9);
           s2.setPhoneNumber(9875643210l);
           studentArray[1]=s2;
          
           //s3 is the third object of class Student
           Student s3 = new Student();
           s3.setName("Student 2");
           s3.setAge(22);
           s3.setGpa(9);
           s3.setPhoneNumber(9875643210l);
           studentArray[2]=s2;
          
           System.out.println("Student(s1) name is "+studentArray[0].getName());
           System.out.println("Student(s1) age is "+studentArray[0].getAge());
           System.out.println("Student(s1) gpa is "+studentArray[0].getGpa());
           System.out.println("Student(s1) phone number is "+studentArray[0].getPhoneNumber());
   }
}

Answer 3) Basic cat class with getters and setters

public class Cat {
  
   private String name;
   private double weight = 15;

   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   public double getWeight() {
       return weight;
   }

   public void setWeight(double weight) {
       this.weight = weight;
   }

//feed method
public void feed(double foodAmount) {
       this.weight += foodAmount/10;
   }

   public Cat() {
   }

}

//Demo class which will feed cat five times

public class DemoCat
   {
   public static void main(String[] args)
   {
   int min = 5, max = 15;
   Cat catObject = new Cat();
   catObject.setName("Lucy");
   catObject.setWeight(15);
  
       for (int i=1 ; i<=5; i++)
       {
           catObject.feed((Math.random() * ((max - min) + 1)) + min);
   }
       System.out.println("The name of the cat is: "+catObject.getName()+"\n"+"The weight of the cat in ounces is: "+catObject.getWeight()+ "and in pounds "+catObject.getWeight()/16);
     
   }
}

Answer 4) Basic book class with getters and setters

public class Book {
   private String bookTitle;
   private float bookPrice;
  
   public String getBookTitle() {
       return bookTitle;
   }

   public void setBookTitle(String bookTitle) {
       this.bookTitle = bookTitle;
   }

   public float getBookPrice() {
       return bookPrice;
   }

   public void setBookPrice(float bookPrice) {
       this.bookPrice = bookPrice;
   }
}

//Demo class for book
import java.util.ArrayList;
import java.util.List;

public class DemoBooks {

   public static void main(String[] args) {
      
       List<Book> bookList = new ArrayList<Book>(1000);
       for(int i=0; i<1000; i++) {
       Book b = new Book();
       b.setBookPrice(1000);
       b.setBookTitle("Book1");
       bookList.add(b);
       System.out.println(b.getBookPrice());
           System.out.println(b.getBookTitle());
       }
      
   }
}