Testing a class help needed

Question

Hi, I have to do the following :
(1)Write a class called Student with the following private member variables:
name [String]
id [long]
marks [float]
(2)It must have the following methods:
Methods to set name, set ID, and set marks
Eg: public void setName(String newName) { … }
Methods getName, getID, getMarks, eg:
public long getID() {
return id;
(3)Note that the set and get methods do not normally display messages on screen. However, setMarks should display an error if the marks are not in the range 0 - 100, and set the member variable marks to 0.
(4)To test the Student class, write a Test Class that creates a Student object and sets its name, ID and marks. The program should then display the student's name and marks in a message box.
Its parts (3) and (4) Im having trouble with. Im not sure is part 3 correct and cant check it if I dont know what to do for part 4
import javax.swing.JOptionPane;
public class Student {
      * OBP
     private String name;  // Student's name.
     private long ID;  // Unique ID number for this student.
     private float marks;   // Grade
     private static int nextUniqueID = 0;
     // keep track of next available unique ID number
     Student(String newName)
          // Names Student, assigns the student a unique ID number
          name = newName;
          nextUniqueID++;
          ID = nextUniqueID;
     public String getName()
          return name;
     public long getID()
          return ID;
     public float getMarks()
          return marks;
     public void setName(String newName)
          name = newName;
     public void setID(long newID)
          ID = newID;
     public void setMarks(float newMarks)
          if (newMarks >=0 && newMarks <=100)
          marks = newMarks;
          else
               JOptionPane.showMessageDialog(null, "Marks must be >=0 and <=100");
               marks=0;
}Im still new to this so be gentle :P
Thanks

Answer 1

pierrot_2 wrote:
>
No, not quite. It means, if you want to do this...
Student mySt = new Student();... then your Student class has to have this...
public class Student{
public Student(){
}... but it doesn't, so you can't.Just figured that one out.
Huh? You're the one who said what the syntax should be with the private variables and public methods etc. So instead of doing this...
mySt.setID;//wrong syntax... you have to follow the rules you wrote in the Student class definition...
mySt.setID((long)34);//right syntax... but then on this particular method, your Student class has already assigned an ID value (in the constructor), so that undermines your own logic.Its an assignment, hence not technically my logic, just doing what it says and now trying to understand it.
... that's what I'd like to know.If you look at the first post its clearly an assignment I needed help with and it tells you what to do, which I (Yes, "I") did, so now trying to do the Test Class and understand it is the tricky bit.
New Student class (so far):
import javax.swing.JOptionPane;
public class Student {
     private String name;  // Student's name.
     private long ID;  // ID number for this student.
     private float marks;   // Grade
     public Student()
     //Removed Unique ID part...Should this do something??
     public String getName()
          return name;
     public long getID()
          return ID;
     public float getMarks()
          return marks;
     public void setName(String newName)
          name = newName;
     public void setID(long newID)
          ID = newID;
     public void setMarks(float newMarks)
          if (newMarks >=0 && newMarks <=100)
               marks = newMarks;
          else
               JOptionPane.showMessageDialog(null, "Marks must be >=0 and <=100");
               marks=0;
}New Test class:
import javax.swing.JOptionPane;
public class Test{
     public static void main(String[] args)
          String newName = "Dave";
          long newID = 8731543;
          float newMarks = 1010;
          Student mySt = new Student();
          mySt.setName(newName);
          mySt.setID(newID);
          mySt.setMarks(newMarks);
          JOptionPane.showMessageDialog(null, "Name: " + newName + " Marks: " + newMarks );
}The error message that mark is >100 comes up but then so does "Name: Dave Marks:1010.0" even though marks should be set to 0?
Am I still far off? Its 2:45am here and I need to hand this in as soon as possible so am I in for an all nighter?