help creating mutator

[Kamran Khaen]

the task is

add a method signUp()which will allow a student to sign up for the race meeting. When a student signs up for the meeting, their achievements points are incremented by the attendance points of the race meeting, they are added to the team and the cost for the meeting is added to the contest's total costs. Seniors pay £10, juniors pay half of the costs, matures pay the full cost.

my meeting class is

public class Meeting
{   
    // declare fields
    private String code;
    private Date raceDate;
    private double cost;
    private int points;
    private double totalCosts = 0;
    //2.1
    private String venue;
    private int numberOfPlaces;

    private ArrayList<Student> team; 
    
    public Meeting (String code, String Location, int noOfPlaces, int AttendancePoints, double Cost,
    int day, int month, int year) 
    {
        code = code;
        venue = Location;
        numberOfPlaces = noOfPlaces;
        points = AttendancePoints;
        cost = Cost;
        raceDate = new Date (day,month,year);
        team = new ArrayList < Student > ();
    }
        
    
    
 
    /** 
     * returns the meeting code
     * @return the meeting code
     */
    public String getCode()
    {
        return code;
    }
       
    /** returns the meeting attendance points
     * @return the meeting attendance points
     */ 
    public int getPoints()
    {
        return points;
    } 
    
    /** returns the total costs collected for the meeting
     * @return the total costs collected for the meeting
     */
    public double getTotalCosts()
    {   
        return totalCosts;  // all the work for this is done in signUp()
    }

    
    /** Withdraws one Student from this race meeting
     * - see specification for details
     */
    public void withdraw(Student m)
    {
        if (team.contains(m))   // optional
        {
            team.remove(m);
            m.decrementPts(points);
        }
    }
    

    /** Returns true if a student is signed up for the meeting
     * @return true if a student is signed up for the meeting
     */
    public boolean isSignedUp(Student m)  
    {   
        return team.contains(m); // return a suitable value
    }
    //2.3
    public void setRaceDate(int d,int m,int y)
    {
       raceDate.setDate(d,m,y);
    
    } 
   // 2.3
    public String getVenue()
    {
        return code;
    }
    public double getCost()
    {
        return cost;
    }
    public Date getRaceDate()
    {
        return raceDate;
    }
    public String getMeetingDetails()
    {
        String MeetingDetails = "Code: " + code + "at " + venue + "on " + raceDate + "cost: " + 
        totalCosts + "Maximum Students" + "20";
        return MeetingDetails;
       
    }    
      
  
}

any my student class is

public class Student                                
{
    // fields                
    private String name;  
    private int achievementPts;
    private int age;
    //1.1
    private int idNumber;
 
    /**
    * Creates a Student with a unique id number and a name initialised from 
    * parameter values, 
    * @param id it is the responsibility of the client to ensure that id is a unique number
    * @param n is the String representation of the Student's name
    * @param age is the strudent's age
    */ 
    public Student (String n, int age)    
    {             
        name = n;
        achievementPts = 0;
        this.age = age;
        //1.1
        idNumber = 0;
        
    }
    
    /**
    * returns Student's achievement points as an int
    * @return value returned is Student achievement points as an int
    */ 
    public int getAchievementPts ()
    {
        return achievementPts;                                
    }
    
    /**
    * returns Student's age
    * @return value returned is Student achievement points as an int
    */ 
    public int getAge ()
    {
        return age;                                
    }
    

   /**
    * allows a Students achievementPts to be decremented
    * @param pts is the number by which a Student's achievementPts will be incremented
    */ 
    public void decrementPts (int pts)
    {
        achievementPts = achievementPts - pts;                                
    }    
        
    /**
    * returns whether the player is a junior or not
    * @return value true if player is a junior
    */ 
    public boolean isJunior()
    {
        return age < 18 ;                                
    }
    
    /**
    * returns whether the player is a mature or not
    * @return value true if player is a mature
    */ 
    public boolean isMature ()
    {
        return age > 21;                                
    }
    //1.2
    public int getId()
    {
        return idNumber;   
    }
    //1.3
    public void incrementPoints(int p)
    {
        achievementPts = achievementPts + p;
    } 
    //1.4
    public boolean isSenior()
    {
        if(age > 17)
        {
            return true;
        }
        else
        {
            return false;
        }    
    } 
    
    //1.6
     public String toString() 
    { 
        String StudentInfo = "Student ID: " + idNumber + 
        "Name: " + name + 
        "Points: " + achievementPts + 
        "Age: " + age + //;
        "Type: "  ;     
        return StudentInfo; 
    } 
}

anyone think they can crack it kinda stuck and dont know wher to begin

[Christophe Verré]

What's a mutator ?

public class Student {
	...
	public void eatSmellyPizza() {
		System.out.println(name + " has turned into a mutant.");
	}
}

Seriously, you'll have to tell us concretely what your problem is, not just write your assignement like that. Remember that the ranch is NotACodeMill. If there are many problems, break them into small problems.

1. Where do you add the signUp method ? What's its parameters ?
2. Increment the student's achievement points
3. Add the student to the team
4. Increase contest's total costs (value depends on the age of the student)

[Kamran Khaen]

i add the the mutator to the meeting class, im jus confused on how to do what is asked. im not asking you to rite the code for me. could you please write and example and explain the method which in contrast to what im asking.

im confused on the points 234 above

not so sure on how to do these

2. Increment the student's achievement points
3. Add the student to the team
4. Increase contest's total costs (value depends on the age of the student)

[Christophe Verré]

2. Increment the student's achievement points

There's a method called incrementPoints in the Student class.

[Kamran Khaen]

Christophe Verré wrote:

2. Increment the student's achievement points

There's a method called incrementPoints in the Student class.

ok I figured out that I do a method call, but how do I add the student to the team

[Christophe Verré]

The Meeting class holds a team variable, which is an ArrayList of Student. If you pass the Student to the signUp method, you should be able to add the student to the team.

[Kamran Khaen]

ok bessically, ive just gone back and found an error, i have to create a method to allow a student to signup for the race meeting, this is the first thing i need to do

i have another class called Society which has created an arraylist for meeting the class is posted below

import java.util.*;

public class Society
{   
    private String location;
    private ArrayList<Meeting> allMeetings= new ArrayList<Meeting>();
    
    /** A constructor for the Society
     */
    public Society(String loc)
    {
        this.location = loc;
    }
 
    
    /** Adds a race meeting to the Society
     */
    public void addMeeting(Meeting ral)
    {
        if (!allMeetings.contains(ral))
        {
            allMeetings.add(ral);
        }
        else
        {System.out.println("Meeting already exists");}
    }   
    
    /** Allows a Student to withdraw from a race meeting
     */
    public void withdrawFromMeeting(Student m, Meeting r)
    // note: points handled in Meeting
    {
        if (r.isSignedUp(m))  
        {
            r.withdraw(m);    
        }
        else
        {System.out.println("Student not signed up for this RaceMeeting");}
    }
    
    /** Displays all race meetings in the Terminal Window
     */
    public void printAllMeetings()
    {
        for (int index = 0; index <allMeetings.size(); index++ )
        {
            Meeting r = allMeetings.get(index);
            System.out.println(r.toString()); 
        }
    } 

    
    /** returns true if the code given as by the parameter value 
     * is the code for a Meeting at the Society, false otherwise
     * @return true if the code given as by the parameter value 
     * is the code for a Meeting at the Society, false otherwise
     */
    public boolean isMeeting(String t)
    {
        for (Meeting temp : allMeetings)
        {
            if (t.equals(temp.getCode()))
            {
                return true;
            }
        }
        return false;
    }
    
}

do I use this array list to add the student to the race meeting
>

[Kamran Khaen]

to add a student i used this code but its giving an error

    public void signUp(String s)
    {
        Student.add(s);

    }    
      

[Christophe Verré]

do I use this array list to add the student to the race meeting

Not that one. You use the ArrayList of the Meeting class. Try to think logically from here. Tell yourself "how do I add a Student to the ArrayList of the Meeting class ?" From there, you should figure out that you need a method in the Meeting class to add Students.

[Kamran Khaen]

ok this is the code ive used for the signup method it worked anyone know if its correct

 public void signUp(Student std)
    {
        if(team.size() < maxStudents)
        {
            team.add(std);
        
           if(std.isJunior())
           totalCosts = 10;
        
          if(std.isSenior())
           totalCosts = (cost/2.0);
        
          if(std.isMature())
           totalCosts = cost;
        std.incrementPoints(points);
    }

[Christophe Verré]

It looks good. Maybe you'll have to check that the Student is not already in the team.
However, the totalCost is being reinitialized every time you add a Student. You'll have to fix this.

[Kamran Khaen]

Christophe Verré wrote:It looks good. Maybe you'll have to check that the Student is not already in the team.
However, the totalCost is being reinitialized every time you add a Student. You'll have to fix this.

how do i fix it?, do I put this. infront of it?

[Christophe Verré]

1. There's a isSignedUp method in the Meeting class that you can use
2. About totalCost, do you know how to add a value to another value ?