Create a basic data management system for students

[rawd allan]

In this exercise, you will create a basic data management system for students in the
Department of Industrial Engineering and Management.
You must write two classes – Student class from exercise 2, and StudentChart.
Student class consists of student data. StudentChart class contains data on all students.
(Up to 100 students may be studying at any one time).
For this purpose, you must fulfill the following interfaces (note - fields of the objects
should be marked as private).
Class: Student chart
Class of Student Chart contains data for all students. Department of studying students
at any one time are up to100 . Way to add a student, is by method addStudent only. At
the beginning of the course each student has not been added, the number of students
enrolled in the Department is 0. Think what would be the fields of this class, so that
you can know much information at any one time.

[salvin francis]

Hi, First of all, welcome to coderanch !
I suggest that you first have a look at our forum rules:
DoYourOwnHomework <-- it’s a link
ShowSomeEffort <-- it’s a link

What have you done so far ? Where are you stuck at ?

[rawd allan]

salvin francis wrote:Hi, First of all, welcome to coderanch !
I suggest that you first have a look at our forum rules:
DoYourOwnHomework <-- it’s a link
ShowSomeEffort <-- it’s a link

What have you done so far ? Where are you stuck at ?

actually I've stock at the first , i did not understands what the program needs ? also I should submit it tomorrow
i need at first to know what is the data fields of the student Chart  class and if the student class extends the Student Chart class or not
thank you for you help      

[salvin francis]

rawd allan wrote:actually I've stock at the first    

I think you probably mean "stuck"

rawd allan wrote: i did not understands what the program needs ?

Lets start by writing some code, your problem statement says that you need to write two classes : Student and StudentChart, can you share what you have done so far ?
Next, I feel that the question you posted is incomplete, it requires some more information present in "exercise 2" which you have not shared.
I presume that it could include Student details such as firstName, lastName, etc...

rawd allan wrote:student class extends the Student Chart class

Why do you think that Student should extend Student Chart ?

[Campbell Ritchie]

Welcome to the Ranch again.

I am afraid that we take no notice of any urgency of requests.
Please start by re‑reading the instructions. What does it say about Student and StudentGraph?
What fields would you put into a Student object? What data would you think a Student would need?

[rawd allan]

salvin francis wrote:

rawd allan wrote:actually I've stock at the first    

I think you probably mean "stuck"

rawd allan wrote: i did not understands what the program needs ?

Lets start by writing some code, your problem statement says that you need to write two classes : Student and StudentChart, can you share what you have done so far ?
Next, I feel that the question you posted is incomplete, it requires some more information present in "exercise 2" which you have not shared.
I presume that it could include Student details such as firstName, lastName, etc...

rawd allan wrote:student class extends the Student Chart class

Why do you think that Student should extend Student Chart ?

I have finished the student class

[Campbell Ritchie]

. . . in which case, what does the Student class look like?

[rawd allan]

rawd allan wrote:

salvin francis wrote:

rawd allan wrote:actually I've stock at the first    

I think you probably mean "stuck"

rawd allan wrote: i did not understands what the program needs ?

Lets start by writing some code, your problem statement says that you need to write two classes : Student and StudentChart, can you share what you have done so far ?
Next, I feel that the question you posted is incomplete, it requires some more information present in "exercise 2" which you have not shared.
I presume that it could include Student details such as firstName, lastName, etc...

rawd allan wrote:student class extends the Student Chart class

Why do you think that Student should extend Student Chart ?

I have finished the student class

/*
 * In this exercise, we create a basic  data management system for students 
*  in the Department of Industrial Engineering and Management. 
*  Student class an object that contains data for students -
*  with student's name , Social Security number and grades. 
*  All students may have grades  for five courses: 
*  Introduction to programming, introduction to management, 
*  data structures, foundations of economic theory and 
*  introduction to mathematics (grade is an integer from 40 to 100).  
/**
 *
 * 
 */
public class Student {
   private String name;// student name
   private long id; // student identity number
   private int [] grades = new int[5]; // list of student courses grades
   
   //costructor that initialize name and id
   public Student(String name, long id){
       String n = name.toUpperCase();
       name = name.replace(name.charAt(0), n.charAt(0));
       for(int i=0 ; i<name. length(); i++)
>
           if(name.charAt(i)==' ')
               name = name.replace(name.charAt(i+1), n.charAt(i+1));
       this.name = name;
       this.id=id;
       
   }
   
   //copy constructor
   public Student(Student st){
       this.name= st.name;
       this.id = st.id;
   }
   
   //return the student name
   public String getName(){
       return name;
   }
   //returns the student id number
   public long getId(){
       return id;
   }
   
   // returns the course grade accoring to parameter course(course number) 
   public int getGrade(int course){
       if(grades[course]== 0)
           return -1;
       return grades[course];
       
   }
   // set the name of student with parameter name
   public void setName(String name){
       String n = name.toUpperCase();
       name = name.replace(name.charAt(0), n.charAt(0));
       for(int i=0 ; i<name. length(); i++)
>
           if(name.charAt(i)==' ')
               name = name.replace(name.charAt(i+1), n.charAt(i+1));
       this.name = name;
       
   }
   
   //sets the student id with parameter id
   public void setId(long id){
       this.id = id;
   }
   //set the course grade with parameter grade 
   public void setGrade(int course, int grade){
       grades[course]= grade;
   }
    // set all the grades of the student from user
   public void setGrades(int [] g){
       for(int i=0; i< grades.length; i++)
           grades[i]=g[i];
            
   }
   //returns the student average in his course
   public double getAverage(){
       int sum= 0;
       int count =0;
       for(int i=0; i< grades.length; i++){
           if(grades[i]!=-1)
          sum=+ grades[i];
           count++;
       }
       return sum/count*1.0;// compute and return average
       
   }
   
   // takes a student object as a parameter and 
   // return true if it is the same as student parameter
   public boolean equals(Student student){
       if(student.id== this.id)
           return true;
       else
           return false;
   }
   //returns a string that represents the student object
   public String toString(){
       
       String [] g = new String[5];
       for(int i=0; i< grades.length; i++)
           if(grades[i]!= -1)
               g[i]= grades[i]+" ";
               else
               g[i]="no grade";
              
       String n1= "Name:"+ name+"\n"+ "ID:  "+ id +"\n"+ "Grades:"+"\n"+
               "Introduction to Programming - "+g[0] +", Introduction to Management – "+g[1]+
               ", Data Structures – "+g[2]+", Introduction to Economics – "+g[3]+
               ", Introduction to Mathematics – "+g[4];
       
       return n1;               
   }
    
}

[rawd allan]

rawd allan wrote:

rawd allan wrote:

salvin francis wrote:

rawd allan wrote:actually I've stock at the first    

I think you probably mean "stuck"

rawd allan wrote: i did not understands what the program needs ?

Lets start by writing some code, your problem statement says that you need to write two classes : Student and StudentChart, can you share what you have done so far ?
Next, I feel that the question you posted is incomplete, it requires some more information present in "exercise 2" which you have not shared.
I presume that it could include Student details such as firstName, lastName, etc...

rawd allan wrote:student class extends the Student Chart class

Why do you think that Student should extend Student Chart ?

I have finished the student class

the output should be like : Prints the students data for all students as follow:
Student number 1:
<Student String representation>
Student number 2:
<Student String representation>
…
Student number <n>:
<Student String representation>
If there are no students print:
void printStudentChart() No students!

/*
 * In this exercise, we create a basic  data management system for students 
*  in the Department of Industrial Engineering and Management. 
*  Student class an object that contains data for students -
*  with student's name , Social Security number and grades. 
*  All students may have grades  for five courses: 
*  Introduction to programming, introduction to management, 
*  data structures, foundations of economic theory and 
*  introduction to mathematics (grade is an integer from 40 to 100).  
/**
 *
 * 
 */
public class Student {
   private String name;// student name
   private long id; // student identity number
   private int [] grades = new int[5]; // list of student courses grades
   
   //costructor that initialize name and id
   public Student(String name, long id){
       String n = name.toUpperCase();
       name = name.replace(name.charAt(0), n.charAt(0));
       for(int i=0 ; i<name. length(); i++)
>
           if(name.charAt(i)==' ')
               name = name.replace(name.charAt(i+1), n.charAt(i+1));
       this.name = name;
       this.id=id;
       
   }
   
   //copy constructor
   public Student(Student st){
       this.name= st.name;
       this.id = st.id;
   }
   
   //return the student name
   public String getName(){
       return name;
   }
   //returns the student id number
   public long getId(){
       return id;
   }
   
   // returns the course grade accoring to parameter course(course number) 
   public int getGrade(int course){
       if(grades[course]== 0)
           return -1;
       return grades[course];
       
   }
   // set the name of student with parameter name
   public void setName(String name){
       String n = name.toUpperCase();
       name = name.replace(name.charAt(0), n.charAt(0));
       for(int i=0 ; i<name. length(); i++)
>
           if(name.charAt(i)==' ')
               name = name.replace(name.charAt(i+1), n.charAt(i+1));
       this.name = name;
       
   }
   
   //sets the student id with parameter id
   public void setId(long id){
       this.id = id;
   }
   //set the course grade with parameter grade 
   public void setGrade(int course, int grade){
       grades[course]= grade;
   }
    // set all the grades of the student from user
   public void setGrades(int [] g){
       for(int i=0; i< grades.length; i++)
           grades[i]=g[i];
            
   }
   //returns the student average in his course
   public double getAverage(){
       int sum= 0;
       int count =0;
       for(int i=0; i< grades.length; i++){
           if(grades[i]!=-1)
          sum=+ grades[i];
           count++;
       }
       return sum/count*1.0;// compute and return average
       
   }
   
   // takes a student object as a parameter and 
   // return true if it is the same as student parameter
   public boolean equals(Student student){
       if(student.id== this.id)
           return true;
       else
           return false;
   }
   //returns a string that represents the student object
   public String toString(){
       
       String [] g = new String[5];
       for(int i=0; i< grades.length; i++)
           if(grades[i]!= -1)
               g[i]= grades[i]+" ";
               else
               g[i]="no grade";
              
       String n1= "Name:"+ name+"\n"+ "ID:  "+ id +"\n"+ "Grades:"+"\n"+
               "Introduction to Programming - "+g[0] +", Introduction to Management – "+g[1]+
               ", Data Structures – "+g[2]+", Introduction to Economics – "+g[3]+
               ", Introduction to Mathematics – "+g[4];
       
       return n1;               
   }
    
}

[Campbell Ritchie]

Please always use the code button I have been back to your post and used the code button on your code, just this once, and doesn't it look better . I think the > in ine 24 (and 59) is there by our mistake.
I am pleased to see you know how to indent your code
What sort of comment is that supposed to be at the start of the class? Is it a block or documentation comment?
Why are you doing that relacing of upper‑case letters in the constructor? What does that do? If you are short of time, I think you have got more important things to think about; also why are you removing spaces? I haven't looked at the details of the replace() method for a long time, but I am 99% sure that it doesn't do what you want.
Why have you got a copy constructor? Do you need to copy a Student ever?
Why are you returning −1 in lines 49‑50? I think you will have to work out a different way to return something, because 0 is a valid result for a course. Notice the inconsistency with line 85.
You will get more marks if you are consistent about spacing: look at line 49.
Your setName() method duplicates code from the constructor. Find a way to avoid such duplication.
Do you want a method to set the Student's id? Will that value ever change?
Add {} to line 76. Explain why it is a very good idea to copy an array like that.
The equals() method must be overridden, which you are not doing. That method can accept two Students with different names as equal. Don't write if (b) return true; else return false; The od Sun Style Guide will tell you what to write instead.

[rawd allan]

Campbell Ritchie wrote:Please always use the code button I have been back to your post and used the code button on your code, just this once, and doesn't it look better . I think the > in ine 24 (and 59) is there by our mistake.
I am pleased to see you know how to indent your code
What sort of comment is that supposed to be at the start of the class? Is it a block or documentation comment?
Why are you doing that relacing of upper‑case letters in the constructor? What does that do? If you are short of time, I think you have got more important things to think about; also why are you removing spaces? I haven't looked at the details of the replace() method for a long time, but I am 99% sure that it doesn't do what you want.
Why have you got a copy constructor? Do you need to copy a Student ever?
Why are you returning −1 in lines 49‑50? I think you will have to work out a different way to return something, because 0 is a valid result for a course. Notice the inconsistency with line 85.
You will get more marks if you are consistent about spacing: look at line 49.
Your setName() method duplicates code from the constructor. Find a way to avoid such duplication.
Do you want a method to set the Student's id? Will that value ever change?
Add {} to line 76. Explain why it is a very good idea to copy an array like that.
The equals() method must be overridden, which you are not doing. That method can accept two Students with different names as equal. Don't write if (b) return true; else return false; The od Sun Style Guide will tell you what to write instead.

i am not sure that I've really understand your suggestion because my teacher discussed the code with me and she said it was very good and agreed to it because we are learning the  object oriented programming  

[Campbell Ritchie]

Yes, it is good object‑oriented code. But I can see a lots of potential improvements.

[rawd allan]

Campbell Ritchie wrote:Yes, it is good object‑oriented code. But I can see a lots of potential improvements.

the important thing for me now is how create the chart class using the data on the student class To achieve the previous output

[rawd allan]

rawd allan wrote:

Campbell Ritchie wrote:Yes, it is good object‑oriented code. But I can see a lots of potential improvements.

the important thing for me now is how create the chart class using the data on the student class To achieve the previous output

does the chart class extend the student class or vice versa ؟

[Campbell Ritchie]

rawd allan wrote:. . . does the chart class extend the student class or vice versa ؟

Please re‑read the instructions. Please explain why a student would be a subtype of student graph. Also why a student graph would be a subtype of student.

[rawd allan]

Campbell Ritchie wrote:

rawd allan wrote:. . . does the chart class extend the student class or vice versa ؟

Please re‑read the instructions. Please explain why a student would be a subtype of student graph. Also why a student graph would be a subtype of student.

There are common fields between the two classes because the student outline contains information about the student such as his name, number and signs

[Dave Tolls]

"Class of Student Chart contains data for all students."

Now, does that sound like a Chart is-a Student (ie extends Student), or a Chart has Students (ie the Chart class has a colleciton of Students)?

[rawd allan]

Stephan van Hulst wrote:Not really, right? The chart contains data on ALL students, not just one.

Besides, just that two types have common fields does not mean one should be the subtype of the other. Does it make sense to say that a student is a graph, conceptually?

so should i start from the beginning and write a chart class ?
there is  No time  just 1 hour  to submit

[Campbell Ritchie]

rawd allan wrote:. . . There are common fields between the two classes because the student outline contains information about the student . . .

Why are you recording information twice? If you have two copies of the information and something changes, that gives you an opportunity to have one correct copy and one incorrect copy

[rawd allan]

Campbell Ritchie wrote:

rawd allan wrote:. . . There are common fields between the two classes because the student outline contains information about the student . . .

Why are you recording information twice? If you have two copies of the information and something changes, that gives you an opportunity to have one correct copy and one incorrect copy

i am not sure that i have really understand my question s what i should use in the chart class what is the data fields ?.

[rawd allan]

rawd allan wrote:

Stephan van Hulst wrote:Not really, right? The chart contains data on ALL students, not just one.

Besides, just that two types have common fields does not mean one should be the subtype of the other. Does it make sense to say that a student is a graph, conceptually?

so should i start from the beginning and write a chart class ?
there is  No time  just 1 hour  to submit

file:///C:/Users/user/Desktop/Dual102_Fall%202018_EX03.pdf

[Campbell Ritchie]

I think the instruction about the chart holding data for students is unclear. I think the chart should contain a list of students and each student object holds its own data. As Stephan and I have tried to hint, the chart is not a subclass of student, and the students are not subclasses of the chart.
A chart HAS‑[A] Students; a Chart IS NOT A Student and a Student IS NOT A Chart.

[rawd allan]

Campbell Ritchie wrote:I think the instruction about the chart holding data for students is unclear. I think the chart should contain a list of students and each student object holds its own data. As Stephan and I have tried to hint, the chart is not a subclass of student, and the students are not subclasses of the chart.
A chart HAS‑[A] Students; a Chart IS NOT A Student and a Student IS NOT A Chart.

Thank you very much
Although the delivery date has been implemented but I must know how to fix it

[Campbell Ritchie]

That's a pleasure

Now, how are you going to read words? Don't answer here.

[Campbell Ritchie]

I only told you that because I knew the hand‑in time had passed; we wouldn't have told you that any earlier.

[rawd allan]

Campbell Ritchie wrote:I only told you that because I knew the hand‑in time had passed; we wouldn't have told you that any earlier.

[rawd allan]

rawd allan wrote:

Campbell Ritchie wrote:I only told you that because I knew the hand‑in time had passed; we wouldn't have told you that any earlier.

public class studentChart {
ArrayList <studentChart> student = new ArrayList <studentChart> ();  
studentChart s=new studentChart();
 
}

[Campbell Ritchie]

That would imply that you are creating multiple charts, which I don't think is the aim of the exercise.

[salvin francis]

rawd allan wrote:

public class studentChart {
  ArrayList <studentChart> student = new ArrayList <studentChart> ();  
  studentChart s=new studentChart();
}

Adding to what campbell pointed out, this looks like:
1. studentChart contains a list of studentChart
2. You're asking java to create an object of studentChart as soon as it loads the class studentChart

Your problem statement mentions something about students, departments and a chart. The code you shared is about Students and you have added grades to them. You have shared no information about what the chart should contain. I think you need first explain the problem more thoroughly. Your posted exercise does not cover the complete requirements.

Can you please share the exact requirements of what you want to achieve ?