Question

Write a class called (d) Teacher that has just a main method. The main method should construct a GradeBook for a class with two students, "Jack" and "Jill". Jack’s grades on the three tests for the class are 33, 55, and 77. Jill’s grades are 99, 66, and 33. After constructing the GradeBook object, main should use the instance methods of the GradeBook class to determine the name of the student with the highest average grades. Print the name of this student on the screen.

Answer 1

Answer:

The java program is given below.

import java.util.*;

class GradeBook  

{

//variables to hold all the given values

static int m11, m12, m13;

static int m21, m22, m23;

static String name1, name2;

//variables to hold the computed values

static double avg1, avg2;

//constructor initializing the variables with the given values

GradeBook()

{

name1 = "Jack";

m11 = 33;

m12 = 55;

m13 = 77;

name2 = "Jill";

m21 = 99;

m22 = 66;

m23 = 33;

}

//method to compute and display the student having highest average grade

static void computeAvg()

{

avg1=(m11+m12+m13)/3;

avg2=(m21+m22+m23)/3;

if(avg1>avg2)

System.out.println("Student with highest average is "+ name1);

else

System.out.println("Student with highest average is "+ name2);

}  

}

//contains only main() method

public class Teacher{  

public static void main(String[] args)

{

//object created

GradeBook ob = new GradeBook();

//object used to call the method

ob.computeAvg();

}

}

OUTPUT

Student with highest average is Jill

Explanation:

1. The class GradeBook declares all the required variables as static with appropriate data types, integer for grades and double for average grade.

2. Inside the constructor, the given values are assigned to the variables.

3. The method, computeAvg(), computes the average grade of both the students. The student having highest average grade is displayed using System.out.println() method.

4. Inside the class, Teacher, the main() method only has 2 lines of code.

5. The object of the class GradeBook is created.

6. The object is used to call the method, computeAvg(), which displays the message on the screen.

7. All the methods are also declared static except the constructor. The constructor cannot have any return type nor any access specifier.

8. The program does not takes any user input.

9. The program can be executed with different values of grades and names of the students.