错误的非法表达开始

Question

I keep getting:

illegal start of expression,';" expected System.exit(0), and reached end of file while parsing

This is the description of what its suppose to do and the code.

Problem to Solve:
How much should I study outside of class?

Issue:
Your fellow students need help. This is their first year in college and they need to determine how many hours they need to study to get good grades.

Study Hrs Per Week Per Credit                 Grade
5:                                            A,
4:                                            B,
3:                                            C,
2:                                            D,
0:                                            F,

Project Specifications:

1. The user enters either the number of hours they plan on studying per week or the grade they want based on the number of credit hours they enter. (Note: Your program must provide the user both options.)
2. The program displays the user's name, number of credits, total number of study hours, and grade they should expect to receive.
3. You may use any programming technique covered in the Intro to Programming Logic course to complete this project. That will require, however, that you read ahead in your textbook for instructions on how to implement the technique in the Java programming language.

Below is my code:

import javax.swing.JOptionPane; //Needed for the dialogue box

/**
    This program shows the student the grade they will receive 
    or how much to study for a certain grade.
*/

public class MoultonAlainaProject1
{
    public static void main(String[] args)
    {
        string wantedGrade, desiredGrade, name, input;
        char finalGrade;
        int gradeA = 5;
        int gradeB = 4;
        int gradeC = 3;
        int gradeD = 2;
        int gradeF = 0;
        float studyHrs;
        int creditHrs, userChoice;

        //Scanner for keyboard input
        Scanner keyboard = new Scanner(System.in);

        name = JOptionPane.showInputDialog("Please enter your name.");

        input = JOptionPane.showInputDialog("How many credit hours do you plan on taking this semester?");
        creditHrs = integer.parseInt(input);

        input = JOption.showInputDialog("If you would like to know the amount of hours you should study for the amount of" + 
                                        "credit hours press 1. If you would like to know the grade you would receive by" +
                                        "entering the amount of hours you plan to study press 2.");
        userChoice = integer.parseInt(input);

        if (userChoice == 1)
        {
            desiredGrade = JOptionPane.showInputDialog("Enter the grade you would like to receive.");

            if (desiredGrade == 'A' || 'a')
            {
                wantedGrade = gradeA;
            }
            else
            {
                if (desiredGrade == 'B' ||'b')
                {
                    wantedGrade = gradeB;
                }
                else
                {
                    if (desiredGrade == 'C' || 'c')
                    {
                        wantedGrade = gradeC;
                    }
                    else
                    {
                        if (desiredGrade == 'D' || 'd')
                        {
                            wantedGrade = gradeD;
                        }
                        else
                        {
                            if (desiredGrade == 'F' || 'f')
                            {
                                wantedGrade = gradeF;
                            }
                            else 
                            {
                                System.out.printIn("Error: you have not entered a valid input.");
                            }
                        }
                    }   
                }
            }   

            studyHrs = wantedGrade * creditHrs; 
        }
    else
    {
        if (userChoice == 2)
        {
            input = JOptionPane.showInputDialog("Enter the amount of hours you plan to study a week.");
            studyHrs = integer.parseInt(input);

            wantedGrade = studyHrs/creditHrs;

            if (wantedGrade >= 5)
            {
                finalGrade = "A";
            }
            else
            {
                if (wantedGrade >= 4)
                {
                    finalGrade = "B";
                }
                else 
                {
                    if (wantedGrade >= 3)
                    {
                        finalGrade = "C";
                    }
                    else
                    {
                        if (wantedGrade >= 2)
                        {
                            finalGrade = "D";
                        }
                        else
                        {
                            if (wantedGrade < 2)
                            {
                                finalGrade = "F";
                            }
                        }
                    }
                }
            }

        JOptionPane.showMessageDialog(null, name+ ", you are taking " +creditHrs+ "credit hours, you should study " +studyHrs+ " hours a week to receive " +finalGrade+ " in your classes." 

        System.exit(0);
    }
}   

I have checked the braces a ton of times but I probably missed something somewhere

Answer 1

You have about 20 compile time errors.
I see missing imports, string written with lowercase, unclosed brackets,
unclosed curly braces, assigning string values to char variables, etc.
See below and fix them.

    Description Resource    Path    Location    Type
    Type mismatch: cannot convert from String to char   MoultonAlainaProject1.java  /TEST/src   line 107    Java Problem
    Type mismatch: cannot convert from String to char   MoultonAlainaProject1.java  /TEST/src   line 101    Java Problem
    Type mismatch: cannot convert from String to char   MoultonAlainaProject1.java  /TEST/src   line 95 Java Problem
    Type mismatch: cannot convert from String to char   MoultonAlainaProject1.java  /TEST/src   line 89 Java Problem
    integer cannot be resolved  MoultonAlainaProject1.java  /TEST/src   line 83 Java Problem
    The method printIn(String) is undefined for the type PrintStream    MoultonAlainaProject1.java  /TEST/src   line 69 Java Problem
    integer cannot be resolved  MoultonAlainaProject1.java  /TEST/src   line 33 Java Problem
    JOption cannot be resolved  MoultonAlainaProject1.java  /TEST/src   line 30 Java Problem
    Syntax error, insert "}" to complete MethodBody MoultonAlainaProject1.java  /TEST/src   line 124    Java Problem
    Syntax error on token(s), misplaced construct(s)    MoultonAlainaProject1.java  /TEST/src   line 122    Java Problem
    exit cannot be resolved or is not a field   MoultonAlainaProject1.java  /TEST/src   line 122    Java Problem
    Syntax error on token(s), misplaced construct(s)    MoultonAlainaProject1.java  /TEST/src   line 120    Java Problem
    Type mismatch: cannot convert from String to char   MoultonAlainaProject1.java  /TEST/src   line 113    Java Problem
    Syntax error, insert "}" to complete ClassBody  MoultonAlainaProject1.java  /TEST/src   line 9  Java Problem
    Scanner cannot be resolved to a type    MoultonAlainaProject1.java  /TEST/src   line 23 Java Problem
    string cannot be resolved to a type MoultonAlainaProject1.java  /TEST/src   line 12 Java Problem
    integer cannot be resolved  MoultonAlainaProject1.java  /TEST/src   line 28 Java Problem
    Scanner cannot be resolved to a type    MoultonAlainaProject1.java  /TEST/src   line 23 Java Problem

Answer 2

 JOptionPane.showMessageDialog(null, name+ ", you are taking " +creditHrs+ "credit hours, you should study " +studyHrs+ " hours a week to receive " +finalGrade+ " in your classes." 

The showMessageDialog()-method is not complete. You are missing a closing bracket and semicolon.