Student Marks Calculator

Question

Hi I have a question from class, this is my first attempt at Java programming:
Write a Java application program that calculates a student?s final course mark, which is comprised of a total assignment mark, mid-term exam mark, and final exam mark.
Input:
Use JOptionPane to enter the following input values;
a.     Enter a student name.
b.     Enter total assignment mark (max. 140) (an integer value)
c.     Enter mid-term exam mark (max. 60) (an integer value)
d.     Enter final exam mark (max. 85) (an integer value)
Processing:
1.     A student?s final mark is weighted as follow:
a.     Assignments are worth 15% of the final mark
b.     The mid-term is worth 40% of the final mark
c.     The final exam is worth 45% of the final mark
2.     Store the maximum mark values (140, 60, 85) as named integer constants
3.     Store the weighted values as named integer constants
4.     Find the weighted values for each of the three categories in step 2 above by using the formula:
student mark / maximum value x weighted value.
5.     Sum the three weighted results to arrive at the final student mark. Express the final mark as a double.
This is the code I did so far, but it won't work gives an err: F:\Java Programming\Term Assignments\2\StudentMarksCalc.java:46: not a statement
          (TOTAL_ASSIGNMENT_MARK / MAX_ASSIGNMENT_MARK * WEIGHTED_ASSIGNMENT
          ^
1 error
Tool completed with exit code 1
So here's the code:
import javax.swing.JOptionPane;
public class StudentMarksCalc
{ //Start StudentMarksCalc class
     public static void main(String[] args)
          // Define and initialize variables
          int STUDENT_NAME; // student name
          int TOTAL_ASSIGNMENT_MARK; //assignment mark
          int MIDTERM_EXAM_MARK; //midterm assignment mark
          int FINAL_EXAM_MARK; // final exam mark
          int MAX_ASSIGNMENT_MARK = 140; //maximum assignment mark
          int MAX_MIDTERM = 60; //maximum midterm mark
          int MAX_FINAL = 85; //maximum final mark
          int STUDENT_MARK = 0; // student mark
          int WEIGHTED_ASSIGNMENT = 0.15;
          int WEIGHTED_MIDTERM = 0.4;
          int WEIGHTED_FINAL = 0.85;
          // Get input from user
          STUDENT_NAME = JOptionPane.showInputDialog("What is "+ "your name? ");
          TOTAL_ASSIGNMENT_MARK = JOptionPane.showInputDialog("Enter your "+ "total assignments mark ");
          MIDTERM_EXAM_MARK = JOptionPane.showInputDialog("Enter your "+ "midterm exam mark ");
          FINAL_EXAM_MARK = JOptionPane.showInputDialog("Enter your "+ "final exam mark ");
          //Convert the strings (old)
          STUDENT_MARK=Double.parseDouble(inputString);
          // Convert the strings to an int
     //STUDENT_MARK= Integer.parseInt(str);
          //Calculate the weighted marks student mark / maximum value x weighted value
          (TOTAL_ASSIGNMENT_MARK / MAX_ASSIGNMENT_MARK * WEIGHTED_ASSIGNMENT
          + MIDTERM_EXAM_MARK / MAX_MIDTERM * WEIGHTED_MIDTERM
          + FINAL_EXAM_MARK / MAX_FINAL * WEIGHTED_FINAL = STUDENT_MARK;
          //Display The results
          JOptionPane.showMessageDialog(null, "Hello " + STUDENT_NAME );
// End the program.
System.exit(0);
}

Answer 1

It seems that you are mixing int and double values leading to 'possible loss of precision' error.
Further, in calculating the marks, the equation should be the other way around; that means that you have to transpose the STUDENT_MARK variable; like STUDENT_MARK = <calculation>.
Also, you cannot directly assign the return value from JOptionPane to an int or double because the return value is a String. It has to be like this is you are using double:
FINAL_EXAM_MARK = Double.parseDouble(JOptionPane.showInputDialog("Enter your "+ "final exam mark "));
For int, it will be like this:
FINAL_EXAM_MARK = Integer.parseInt(JOptionPane.showInputDialog("Enter your "+ "final exam mark "));
I hope this answers your question.