Need help in doing exercise with classes

Question

Here is my exercise:
1.     An object Student has: id, last name, first name, number of AAS courses and number of ESL courses in current semester and whether student uses laptop or not.
The formular to calculate tuition fee:
Tuition fee = AAS courses *20 ESL courses * +15+
+If student uses laptop, tuition fee will be deducted 5%
Write the methods to:
o     Calculate tuition fee.
o     Display student information
My Student class:
public class Student {
     private String id;
     private String lastName;
     private String firstName;
     private double nAAS;
     private double nESL;
     public void setIdentification(String input) {
          id = input;
     public void setLastName(String input) {
          lastName = input;
     public void setFirstName(String input) {
          firstName = input;
     public String getID() {
          return id;
     public String getLastName() {
          return lastName;
     public String getFistName() {
          return firstName;
     public void setNumberOfAAS(String input) {
          nAAS = Double.parseDouble(input);
     public void setNumberOfESL(String input) {
          nESL = Double.parseDouble(input);
     public double getNumberOfAAS() {
          return nAAS;
     public double getNumberOfELS() {
          return nESL;
     public double result(String input) {
          if (input.equalsIgnoreCase("true")) {
               return (getNumberOfAAS() * 20 + getNumberOfELS() * 15) * 0.95;
          } else {
               return getNumberOfAAS() * 20 + getNumberOfELS() * 15;
}And my DisplayResult class:
import javax.swing.JOptionPane;
public class DisplayResult {
     public static void main(String[] args) {
          String input;
          Student st = new Student();
          input = JOptionPane.showInputDialog("Enter the ID here:");
          st.setIdentification(input);
          input = JOptionPane.showInputDialog("Enter the last name:");
          st.setLastName(input);
          input = JOptionPane.showInputDialog("Enter the first name:");
          st.setFirstName(input);
          input = JOptionPane
                    .showInputDialog("Enter number of AAS courses you took:");
          st.setNumberOfAAS(input);
          input = JOptionPane
                    .showInputDialog("Enter number of ESL courses you took:");
          st.setNumberOfESL(input);
          input = JOptionPane
                    .showInputDialog("Enter \"true\" for using laptop and \"false\" if not:");
          st.result(input);
          // Display the result
          JOptionPane.showMessageDialog(null, "The result is:\n" + st.getID()
                    + " " + st.getLastName() + " " + st.getFistName()
                    + "\nYou have: " + st.getNumberOfAAS() + " AAS "
                    + st.getNumberOfELS() + " ESL\n" + "Using laptop: " + input
                    + "\nYour tuitionFee is: "
                    + st.result());
System.exit(0);
}The eclipse notice an error which is st.result in DisplayResult class. Please tell my what 's wrong with it?
Edited by: congtm88 on May 4, 2009 9:43 AM

Answer 1

Oh thax. I corrected it.
     public static void main(String[] args) {
          String input;
          Student st = new Student();
          input = JOptionPane.showInputDialog("Enter the ID here:");
          st.setIdentification(input);
          input = JOptionPane.showInputDialog("Enter the last name:");
          st.setLastName(input);
          input = JOptionPane.showInputDialog("Enter the first name:");
          st.setFirstName(input);
          input = JOptionPane
                    .showInputDialog("Enter number of AAS courses you took:");
          st.setNumberOfAAS(input);
          input = JOptionPane
                    .showInputDialog("Enter number of ESL courses you took:");
          st.setNumberOfESL(input);
          input = JOptionPane
                    .showInputDialog("Enter \"true\" for using laptop and \"false\" if not:");
          // Display the result
          JOptionPane.showMessageDialog(null, "The result is:\n" + st.getID()
                    + " " + st.getLastName() + " " + st.getFistName()
                    + "\nYou have: " + st.getNumberOfAAS() + " AAS "
                    + st.getNumberOfELS() + " ESL\n" + "Using laptop: " + input
                    + "\nYour tuitionFee is: "
                    + st.result(input));
System.exit(0);
     }But I think that, I should change result method into useOfLaptop then write one more instance method name getResult in Student class, right?