Thread: gradebook

Hey guys new to the forum and im a beginner with java and I need to write a basic gradebook program. Part of our assignment is to
"Add the following method header outside your main method, but still inside your GradeBook class:
public static char calculateGrade(double score) { }
The body of this method will perform the task of translating a numeric value into a letter grade. To accomplish this task, the method accepts a double value, representing a single score, and returns a char value of either ‘A’, ‘B’, ‘C’, ‘D’ or ‘F’. Within the method body, you will need to use a nested selection statement, like the one shown on page 82 of the 10th Edition textbook.
The calculateGrade() method should be invoked AFTER the user inputs a score. Following the invocation of calculateGrade(), the program should output a message like “The score 72.0 is a C” for every score that is entered. Because calculateGrade() returns a char value, a switch can be used to print this output message."

I dont know how to incorporate that into the program i have so far.

import java.util.Scanner; // program uses class Scanner

public class Gradebook {

public static void main (String[] args) {

Scanner keyboard= new Scanner(System.in);

int numberofgrades= 0;
double grade= 0;
double avg= 0;
double sum= 0;
int A,B,C,D,F;

A=0;
B=0;
C=0;
D=0;
F=0;

System.out.println ("Enter a grade between 0 and 100 and type -1 when you are finished.");

do{

grade=keyboard.nextInt();

if(grade !=-1){


sum= sum + grade;

}

if(grade >= 0.0){
numberofgrades++;


if(grade>=90.0 && grade <= 100.0){

A++;

}
if(grade>=80.0 && grade <= 89.9){



B++;

}

if(grade>=70.0 && grade <= 79.9){



C++;

}

if(grade>=60.0 && grade <= 69.9){



D++;

}

else if(grade>=0.0 && grade <= 59.9){




F++;
}

}

}

while (grade >= 0.0);

avg= sum/ numberofgrades;
System.out.println("Total number of grades is "+ numberofgrades);
System.out.println("Total number of A's is "+A);
System.out.println("Total number of B's is "+B);
System.out.println("Total number of C's is "+C);
System.out.println("Total number of D's is "+D);
System.out.println("Total number of F's is "+F);
System.out.println("Average score is "+ avg);

}


}



Let me know. Thanks.

Looks like you need to make a class called GradeBook and inside that class make the calculateGrade() method. it should take in a double as a parameter. Like calculateGrade(double grade){} then you want your grade selection code that you have in your main method in that method, but instead of increment the amount of people who received that grade, instead System.out.println("The score " + grade + " is a C"); But instead of just C, put whatever grade falls under the proper selection. It can also increment the amount of grades recieved like you already have. Then in your main method you could set grade = 0, then

System.out.println("Enter grade or -1 to exit: ");
grade = keyboard.nextInt();
while (grade != -1)
System.out.println("Enter grade or -1 to exit: ");
grade = keyboard.nextInt();
gradeCalc.calculateGrade(grade);
}

The calculateGrade(grade) will then print out a message saying what grade that score is and increment the grade counter. You should also put a check in calculateGrade to make it exit if grade == -1 in order for the while loop i said to work. If they entered -1 calculateGrade() would exit, then it would go to beginning of while loop and be like "oop! we are done!" then carry on with the rest of your main method.

I hope that helps and answers your question.