How can I build my for loop in this GPA Calculator? Brand new to Java, and for our class we are required to ask for user's grade and credit hours 4 times, then calculate their average. We were instructed to use switch statements and loops, but not much other instruction. We just learned about for, while, and do loops. Here is what I have so far, not sure what to do next.

This is what output is supposed to look like.

    public static void main(String[] args) {
        
        String grade = "";
        int creditHour = 0;
        int pointsPerCourse = 0;
        double gpa = 0.0;
        
        Scanner scnr = new Scanner(System.in);
        
        System.out.println("\t\t\tpointsPerCourse Calculator");
        System.out.println("This program will calculate pointsPerCourses based on course grades");
    
        for ();
        {
            System.out.print("Enter grade: ");
            grade = scnr.nextLine();
        
            System.out.print("Enter number of credits for grade: ");
            creditHour = Integer.parseInt(scnr.nextLine());
        }
        
        switch (grade) 
        {
        
        case "A":
            pointsPerCourse = 4 * creditHour;
        case "B":
            pointsPerCourse = 3 * creditHour;
        case "C":
            pointsPerCourse = 2 * creditHour;
        case "D":
            pointsPerCourse = 1 * creditHour;
            
        default:
            pointsPerCourse = 0 * creditHour;
                
        }   
            
        gpa = (double)pointsPerCourse / creditHour;
        
        System.out.printf("The GPA is %.1f ", gpa);

            scnr.close();
        
    }
  }

CodePudding user response：

This is not golang you cant use a for loop like that and you want to put your switch case inside the loop. Someone sugested a while loop but since you only want to loop over 4 times, a proper for loop will do it for you.

for(int i = 0, i < 4, i  ){
 System.out.print("Enter grade: ");
    grade = scnr.nextLine();
    
    System.out.print("Enter number of credits for grade: ");
    creditHour = Integer.parseInt(scnr.nextLine());
    
    switch (grade) 
    {
    
      case "A":
        pointsPerCourse = 4 * creditHour;
      case "B":
        pointsPerCourse = 3 * creditHour;
      case "C":
        pointsPerCourse = 2 * creditHour;
      case "D":
        pointsPerCourse = 1 * creditHour;
        
      default:
        pointsPerCourse = 0 * creditHour;
     }
}

CodePudding user response：

I think you are trying to do this: loop 4 times and add th epoints and credit hours for averaging

import java.util.Scanner;

class Prog {
    public static void main(String[] args) {

        String grade = "";
        int creditHour = 0;
        int creditHourSum = 0;
        int pointsPerCourse = 0;
        double gpa = 0.0;

        Scanner scnr = new Scanner(System.in);

        System.out.println("\t\t\tpointsPerCourse Calculator");
        System.out.println("This program will calculate pointsPerCourses based on course grades");

        for (int i = 0; i < 4; i  ) {
            System.out.print("Enter grade: ");
            grade = scnr.nextLine();

            System.out.print("Enter number of credits for grade: ");
            creditHour = Integer.parseInt(scnr.nextLine());
            creditHourSum  = creditHour;

            switch (grade) {

                case "A":
                    pointsPerCourse  = 4 * creditHour;
                    break;
                case "B":
                    pointsPerCourse  = 3 * creditHour;
                    break;
                case "C":
                    pointsPerCourse  = 2 * creditHour;
                    break;
                case "D":
                    pointsPerCourse  = 1 * creditHour;
                    break;
                default:
                    pointsPerCourse  = 0 * creditHour;
            }
            System.out.println(pointsPerCourse);
        }

        gpa = (double) pointsPerCourse / creditHourSum;
        System.out.println(pointsPerCourse   ", "   creditHourSum);
        System.out.printf("The GPA is %.1f ", gpa);

        scnr.close();

    }
}

OUTPUT

This program will calculate pointsPerCourses based on course grades
Enter grade: A
Enter number of credits for grade: 4
16
Enter grade: E
Enter number of credits for grade: 4
16
Enter grade: B
Enter number of credits for grade: 4
28
Enter grade: C
Enter number of credits for grade: 3
34
34, 15
The GPA is 2.3