Question

Page 1/2 ECE25100 Object Oriented Programming Lab 8: Inheritance Description: The purpose of this lab is to practice inheritance. To get credit for the lab, you need to demonstrate to the student helper that you have completed all the requirements. Question 1: Consider the following detailed inheritance hierarchy diagram in Fig. 1. 1) The Person.java constructor has two String parameters, a first name and a last name. The constructor initializes the email address to the first letter of the first name followed by the first five letters of the last name followed by @yahoo.com. If the last name has fewer than five letters, the email address will be the first letter of the first name followed by the entire last name followed by a yahoo.com. Examples Name Email address Jane Smith [email protected] John Morris JM Erivahoo.com Mary Key Meyyahoo.com 2) public methods in Person used to access modify the instance fields or variables, eget and set methods, respectively 3) a toString method that should return the Person's information 4) Write the Student.java class so that the Student is a subclass of Person and implements the Comparable interface 5) Write the Student constructor. The Student constructor will be called with two String parameters, the first name and the last name of the student. When the student is constructed. the inherited fields my First Name, mylast Name, and my Email Address will be properly initialized, the student's GPA (My Gpa) will be set to 0. The variable lastid Assigned will be properly incremented each time a Student is constructed and the student ID (my Studentid) will be set to the next available ID number as tracked by the class variable, 6) public methods in Student used to access modify the instance fields or variables, i.e, get and set methods, respectively, 7) a toString method in Student that should return the present state of the Student 8) Students are compared to each other by comparing GPAs. Implement the compare To method for the Student class. 9) Write a Test.java and test your code thoroughly.

Answer 1

Solution of Above java code is provided in below code snippets. Code explaination is given in code comments. I have tried to implement the code in very easy to understandable manner. If any more help is needed regarding the code write in comment section.

Person.java

 public class Person {      private String myFirstName;     private String myLastName;      private String myEmailAddress;  /**      * @param myForstName    * @param myLastName     * @param myEmailAddress         */     public Person(String myFirstName, String myLastName) {          super();                this.myFirstName = myFirstName;                 this.myLastName = myLastName;           if(myLastName.length() >= 5) {               myEmailAddress = myFirstName.charAt(0)+""+myLastName.substring(0,5)+"@yahoo.com";               }               if(myLastName.length() < 5) {                        myEmailAddress = myFirstName.charAt(0)+""+myLastName+"@yahoo.com";              }                       }               /* Getter and setterMethods of Person */        public String getMyFirstName() {                return myFirstName;     }       public void setMyFirstName(String myFirstName) {                this.myFirstName = myFirstName;         }       public String getMyLastName() {                 return myLastName;      }       public void setMyLastName(String myLastName) {          this.myLastName = myLastName;   }       public String getMyEmailAddress() {             return myEmailAddress;  }       public void setMyEmailAddress(String myEmailAddress) {          this.myEmailAddress = myEmailAddress;   }               /* Overriding toString() to provide custom implementation */    @Override       public String toString() {              return "First Name: "+getMyFirstName()+" Last Name: "+getMyLastName()+" has EmailAddress: "+getMyEmailAddress();        }                                                } 

Student.java

  public class Student extends Person implements Comparable<Student> {          String myEmailAddress;  private int myStudentID;        double myGPA;   static int lastIDAssigned = 1000;       /**      * @param myFirstName    * @param myLastName     * @param myGPA          * @param myStudentID    */     public Student(String myFirstName, String myLastName) {                 super(myFirstName, myLastName);                 myFirstName = super.getMyFirstName();           myLastName = super.getMyLastName();             myEmailAddress = super.getMyEmailAddress();             myGPA = 0;              lastIDAssigned++;               myStudentID = lastIDAssigned;   }               /* Getter and setterMethods of Student */       public String getMyFirstName() {                return super.getMyFirstName();  }       public void setMyFirstName(String myFirstName) {                super.setMyFirstName(myFirstName);      }       public String getMyLastName() {                 return super.getMyLastName();   }       public void setMyLastName(String myLastName) {          super.setMyLastName(myLastName);        }       public String getMyEmailAddress() {             return super.getMyEmailAddress();       }       public void setMyEmailAddress(String myEmailAddress) {          this.myEmailAddress = myEmailAddress;   }       public int getMyStudentID() {           return myStudentID;     }       public void setMyStudentID(int myStudentID) {           this.myStudentID = myStudentID;         }       public double getMyGPA() {              return myGPA;   }       public void setMyGPA(double myGPA) {            this.myGPA = myGPA;     }               public String superClassToString() {            return super.toString();        }               /* Overriding toString() to provide custom implementation */    @Override       public String toString() {              return super.toString()+" has StudentID: "+getMyStudentID()+" has GPA: "+getMyGPA();    }               /* Implementing ComapreTo method to Provide comparision betwee students on the basis of their GPA */    @Override       public int compareTo(Student student) {                 if(this.getMyGPA() > student.getMyGPA()) {                   System.out.println(this.getMyFirstName()+" "+this.getMyLastName()+" has greater GPA than "+student.getMyFirstName()+" "+student.getMyLastName());                       return 1;               }               if(this.getMyGPA() < student.getMyGPA()) {                   System.out.println(this.getMyFirstName()+" "+this.getMyLastName()+" has less GPA than "+student.getMyFirstName()+" "+student.getMyLastName());                  return -1;              }                                       System.out.println(this.getMyFirstName()+" "+this.getMyLastName()+" has equal GPA to "+student.getMyFirstName()+" "+student.getMyLastName());                   return 0;                                       }                                                        } 

Main.java <Contains driver code of program>

  public class Test {              public static void main(String[] args) {                                /* creating Person Objects */           Person p1 = new Person("Tom", "Pal");           Person p2 = new Person("Peter", "Parker");                              /* Creating Student object and setting their GPA value respectively */          Student s1 = new Student("Scarlett", "Johansson");              s1.setMyGPA(3.2);               Student s2 = new Student("Will", "Smith");              s2.setMyGPA(3.0);                               /* Printing All Person's Info */                System.out.println("List of All People");               System.out.println(p1.toString());              System.out.println(p2.toString());                              System.out.println(s1.superClassToString());            System.out.println(s2.superClassToString());                            /* Printing only Students Info*/                System.out.println("\n\nList of All Students");                 System.out.println(s1.toString());              System.out.println(s2.toString());                              System.out.println("\n\nComparison Of Students");               s1.compareTo(s2);                                       } } 

Output:

Project Run Window Help File Edit Source Refactor Navigate Search Helal FREL Person.java * Student.java Test.java Nationa 3 public class Person { private String myFirstName; private String my LastName; private String myEmailAddress; Console X <terminated> Test (2) (Java Application) C:\Program Files\Java jre 1.8.0_221\bin\javaw.exe (Apr 16, 2020, 3:12:28 PM) List of All People First Name: Tom Last Name: Pal has EmailAddress: [email protected] First Name: Peter Last Name: Parker has EmailAddress: [email protected] First Name: Scarlett Last Name: Johansson has EmailAddress: [email protected] First Name: Will Last Name: Smith_has EmailAddress: [email protected] * * * @param myForstName @param myLastName * @param my EmailAddress * List of All Students First Name: Scarlett Last Name: Johansson has EmailAddress: [email protected] has StudentID: 1001 has GPA: 3.2 First Name: Will Last Name: Smith has EmailAddress: [email protected] has StudentID: 1002 has GPA: 3.0 120 public Person(String myFirstName, String myLa super(); this.myFirstName = my FirstName; this.myLastName = my LastName; if(myLastName.length() >= 5) { my EmailAddress = myFirstName.charAt()+"" Comparison of Students Scarlett Johansson has greater GPA than Will Smith, if(myLastName.length() < 5) { my EmailAddress = my FirstName.charAt(@ } /* Getter and setterMethods of Person */ public String getMyFirstName() { return myFirstName; public void setMyFirstName(String my FirstName, this.myFirstName = myFirstName; 31 320 public String getMy LastName() { return myLastName; 34 36 37 380 public void setMyLastName(String myLastName) this.myLastName = my LastName; } public String getMyEmailAddress() { Writable Smart Insert 26:37: 684 122M of 263M