Answer:
//class to test the Grade class
public class GradeTest{
public static void main(String []args){
//create the grades to be averaged
double [] grades = {23, 45, 67, 12.6};
//create an object of the Grade class and
//pass in the necessary arguments to the constructor
Grade grade = new Grade("John", grades);
//print out the results from the Grade object.
System.out.println("Your name is " + grade.getName());
System.out.println("Your average score is " + grade.getAverage());
System.out.println("Your letter grade is " + grade.getLetterGrade());
}
} //End of the GradeTest class
//The Grade class
class Grade {
//create instance variables
private String name;
private double [] grades;
//constructor for the class
public Grade(String name, double [] grades){
//initialize the instance variables
this.name = name;
this.grades = grades;
}
//method to return the name of the student
public String getName(){
//return the name
return this.name;
}
//method to calculate the average of the grades
public double getAverage(){
double [] grades = this.grades;
//initialize some needed variables
double sum = 0;
double average = 0;
//loop through the grades array and add each element to the sum variable
for(int i =0; i < grades.length; i++){
sum += grades[0];
}
//calculate the average
average = sum / grades.length;
//return the average grade
return average;
}
//method the calculate the letter grade from the average
public char getLetterGrade(){
//initialize some variables
double average = this.getAverage();
char letterGrade;
//check the average and determine its corresponding letter grade
if(average >= 40 && average < 45){
letterGrade = 'E';
}
else if(average >= 45 && average < 50){
letterGrade = 'D';
}
else if(average >= 50 && average < 60){
letterGrade = 'C';
}
else if(average >= 60 && average < 70){
letterGrade = 'B';
}
else if(average >= 70 && average <= 100){
letterGrade = 'A';
}
else {
letterGrade = 'F';
}
//return the letter grade
return letterGrade;
}
} //End of the Grade class
Sample Output:
Your name is John
Your average score is 23.0
Your letter grade is F
Step-by-step explanation:
The code above is written in Java and it contains comments explaining important parts of the code. It also contains a sample output got from running the program. To run this on your machine, copy the code and save in a file named GradeTest.java