Question

I have listed below two functions. Please add these two functions to StudentMath class.

Test it from the Test class

public int divideByZero(int gradeA, int gradeB, int gradeC) {
int numberOfTests = 0;
int gradeAverage = 0;

try
{
gradeAverage = (gradeA + gradeB + gradeC)/numberOfTests;
}
catch(ArithmeticException ex)
{
System.out.println("Divide by zero exception has occured" + ex.getMessage());
}
return gradeAverage;
}

public int ArrayOutOfBoundEception() {
int i = 0;
try {
// array of size 4.
int[] arr = new int[4];

// this statement causes an exception
i = arr[4];

// the following statement will never execute
System.out.println("Hi, I want to execute");

}catch(ArrayIndexOutOfBoundsException ar) {
System.out.println("Array index out of bound exception: " + ar.getMessage());
}catch(Exception ex) {
System.out.println("An exception occured" + ex.getMessage());
}finally {
System.out.println("Finally block is always executed. It is used to close the resources such as database connection or open file, etc.");
}

return i;
}

Part 2

Write the function StudentFeePaid() in the Student class. . (Assume the fee is paid. you can hard code it)

It will return a string which will have the value "PAID" which means the string which you will return will be like String fee = "PAID".

You will write the try/catch and finally block in this function. In the finally block add the following

System.out.println("Finally block was executed");

Overide this function in the StudentMath class [Hint Use Override attribute and super.StudentFeePaid()]

The returned string will have "PAID" in it. You will modify it to "PAID Thank You" in the overridden function

Test it in the StudentTest Class.

---------------------------------------------------------------------------------------------------------

public class Student
{
int gradeA;
int gradeB;
int gradeC;
int average;
Student(int gradeA, int gradeB, int gradeC)
{
this.gradeA = gradeA;
this.gradeB = gradeB;
this.gradeC = gradeC;
}
public int Average()
{
this.average = (this.gradeA + this.gradeC + this.gradeC)/3;
return average;
}
public String AssignLetterGrade()
{
String grade = "";
if(average >= 90)
{
grade = "A";
}
else if((average < 90) && (average >= 80))
{
grade = "B";
}
return grade;
}
public static void main(String[] args)
{
   int grade1 = 80;
   int grade2 = 90;
   int grade3 = 60;
   System.out.println("Instantiate Student class");
   Student stu = new Student(grade1, grade2, grade3);
   int Average = stu.Average();
   System.out.println("The average grade is: " + Average);
   String strStudentGrade = stu.AssignLetterGrade();
   System.out.println("The letter grade is: " + strStudentGrade);
   }
}

------------------------------------------------------------------------------------------------------

public class StudentMath extends Student
{
   public StudentMath(int gradeA, int gradeB, int gradeC)
   {   
       // invoking base-class constructor
       super(gradeA, gradeB, gradeC);
   }
   @Override
   public int Average()
   {
       int newAverage = super.Average() + 5;
       return newAverage;
   }
   @Override
   public String AssignLetterGrade()
   {
       String grade = super.AssignLetterGrade();
       if (grade.equals("A"))
       {
           grade = grade + " : Excellent";
       }
       return grade;
   }
}

-------------------------------------------------------------------------------

public class Test
{
   public static void main(String[] args)
   {
       // TODO Auto-generated method stub
       int gradeA = 90;
       int gradeB = 91;
       int gradeC = 92;
       StudentMath stMath = new StudentMath(gradeA, gradeB, gradeC);
       int average = stMath.Average();
       System.out.println("The average is " + average);
       String grade = stMath.AssignLetterGrade();
       System.out.println(grade + " Excellent");
   }
}

Answer 1

Part A:

class Student
{
int gradeA;
int gradeB;
int gradeC;
int average;
Student(int gradeA, int gradeB, int gradeC)
{
this.gradeA = gradeA;
this.gradeB = gradeB;
this.gradeC = gradeC;
}
public int Average()
{
this.average = (this.gradeA + this.gradeC + this.gradeC)/3;
return average;
}
public String AssignLetterGrade()
{
String grade = "";
if(average >= 90)
{
grade = "A";
}
else if((average < 90) && (average >= 80))
{
grade = "B";
}
return grade;
}
}

class StudentMath extends Student
{
public StudentMath(int gradeA, int gradeB, int gradeC)
{   
// invoking base-class constructor
super(gradeA, gradeB, gradeC);
}
@Override
public int Average()
{
int newAverage = super.Average() + 5;
return newAverage;
}
@Override
public String AssignLetterGrade()
{
String grade = super.AssignLetterGrade();
if (grade.equals("A"))
{
grade = grade + " : Excellent";
}
return grade;
}
//Two new methods provided are added to this class here
public int divideByZero(int gradeA, int gradeB, int gradeC) {
int numberOfTests = 0;
int gradeAverage = 0;

try
{
gradeAverage = (gradeA + gradeB + gradeC)/numberOfTests;
}
catch(ArithmeticException ex)
{
System.out.println("Divide by zero exception has occured" + ex.getMessage());
}
return gradeAverage;
}

public int ArrayOutOfBoundEception() {
int i = 0;
try {
// array of size 4.
int[] arr = new int[4];

// this statement causes an exception
i = arr[4];
// the following statement will never execute
System.out.println("Hi, I want to execute");

}catch(ArrayIndexOutOfBoundsException ar) {
System.out.println("Array index out of bound exception: " + ar.getMessage());
}catch(Exception ex) {
System.out.println("An exception occured" + ex.getMessage());
}finally {
System.out.println("Finally block is always executed. It is used to close the resources such as database connection or open file, etc.");
}

return i;
}
}

public class Test
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
int gradeA = 90;
int gradeB = 91;
int gradeC = 92;
StudentMath stMath = new StudentMath(gradeA, gradeB, gradeC);//object is created

System.out.println("Divide by Zero method is called."+stMath.divideByZero(gradeA, gradeB, gradeC));//methods are called using the object
System.out.println("ArrayIndexOutOfBounds method is called."+stMath.ArrayOutOfBoundEception());
}
}

Part B:

class Student
{
int gradeA;
int gradeB;
int gradeC;
int average;
Student(int gradeA, int gradeB, int gradeC)
{
this.gradeA = gradeA;
this.gradeB = gradeB;
this.gradeC = gradeC;
}
public String StudentFeePaid(){//method definition
String fee=" ";
try{
fee="PAID";//set value to PAID
}
catch(Exception e){
System.out.println("Exception raised");
}
finally{
System.out.println("Finally block was executed");
}
return fee;//return value
}
public int Average()
{
this.average = (this.gradeA + this.gradeC + this.gradeC)/3;
return average;
}
public String AssignLetterGrade()
{
String grade = "";
if(average >= 90)
{
grade = "A";
}
else if((average < 90) && (average >= 80))
{
grade = "B";
}
return grade;
}
}
class StudentMath extends Student
{
public StudentMath(int gradeA, int gradeB, int gradeC)
{   
// invoking base-class constructor
super(gradeA, gradeB, gradeC);
}
@Override
public int Average()
{
int newAverage = super.Average() + 5;
return newAverage;
}
@Override
public String AssignLetterGrade()
{
String grade = super.AssignLetterGrade();
if (grade.equals("A"))
{
grade = grade + " : Excellent";
}
return grade;
}
@Override
public String StudentFeePaid(){//override the method from base class Student
String fee=" ";
try{
fee="PAID Thank You";//set fee to PAID Thank You
}
catch(Exception e){
System.out.println("Exception raised");
}
finally{
System.out.println("Finally block was executed");
}
return fee;//return value
}
}

public class Test
{
public static void main(String[] args)//code provided
{
// TODO Auto-generated method stub
int gradeA = 90;
int gradeB = 91;
int gradeC = 92;
StudentMath stMath = new StudentMath(gradeA, gradeB, gradeC);
Student stu=new Student(gradeA, gradeB, gradeC);
int average = stMath.Average();
System.out.println("The average is " + average);
String grade = stMath.AssignLetterGrade();
System.out.println(grade + " Excellent");
System.out.println(stMath.StudentFeePaid());//call the method
}
}