Solution Review: Letter Grade to GPA

class gpaHelper{

    public static double letterToGPA (String grade) {
        double answer;

        switch (grade) {
            case "A+":
            case "A":
                answer = 4;
                break;

            case "A-":
                answer = 3.7;
                break;

            case "B+":
                answer = 3.3;
                break;

            case "B":
                answer = 3;
                break;

            case "B-":
                answer = 2.8;
                break;

            case "C+":
                answer = 2.5;
                break;

            case "C":
                answer = 2.0;
                break;

            case "C-":
                answer = 1.8;
                break;

            case "D":
                answer = 1.5;
                break;

            case "F":
                answer = 0;
                break;

            default:
                answer = -1;
        }

        return answer;
    }
 public static void main( String args[] ) {
        System.out.println("Grade A: " + letterToGPA("A"));
        System.out.println("Grade D: " + letterToGPA("D"));
        System.out.println("Grade L: " + letterToGPA("L"));
    }
    
}