Question

Hi, I am writing Java code and I am having a trouble working it out. The instructions can be found below, and the code. Thanks.

Instructions

Here are the methods needed for CIS425_Student:

• Constructor: public CIS425_Student( String id, String name, int num_exams )

• Create an int array exams[num_exams] which will hold all exam grades for a student

• Save num_exams for later error checking

• public boolean addGrade( int exam, int grade )
  • Save a grade in the exams[ ] array at index exam
  • If exam is out of range, return false (Note: exams are numbered 1,2,3,....)

• • If OK, save the grade in exams[ ] array and return true

• public int getGrade( int exam )

• • Return grade saved in exams[ ] array at index exam

• • If exam is out of range, return -1

• • If OK, return grade from exams[ ] array

• public String getName( )

• • Return student name

Here are the methods needed for CIS425_Course:

• Constructor, create a class of (int capacity) CIS425_Students

• Use an array: roster[ ] of size capacity to hold the CIS425_Student objects
• Also, save the capacity as a class variable and set an enrolled class variable to
• In Student add accessors to set the ID and get the ID for each student

• public boolean addStudent( String id, String name, int num_exams )

• • Creates a new CIS425_Student( id, name, num_exams ) object and add to the roster[ ] array

• • Check to see if there is space for the new student, if no room, return false

• • Create a new CIS425_Student object and add to the roster[ ] array, return true

• public CIS425_Student findStudent( String id )

• • Find student with id and return object

• • If student cannot be found, return null

• public double computeAverage( int exam )

• • Compute and return the course average on a specific exam ( that is, 1, 2, …) for all the students

• • Check for divide by 0 and other errors

• main( )

• • Create a CIS425_Course of 30 students

• • Add two (2) students: Sally Smarty (B0000001) and Phil Phailure (B0000002), each with 3 exams

• • Output their names and grades

• • Search for these two students and give them a grade of 100 and 60 respectively on exam 1

• • Output a message with the average of the class on exam 1

--------------------------------------------------------------------

Sample console output:

Sally Smarty has a grade of: 100 on exam 1
Phil Phailure has a grade of: 60 on exam 1
Class average for exam 1: 80.0

------------------------------------------------------------

Here is an outline of your program:

package edu.buffalostate.cis425.sp19.assignments.put-your-lastname-here; 

/*
 * don't forget comments
 */
public class CIS425_Student extends Student {
    public CIS425_Student( String id, String name, int num_exams ) { }
    public boolean addGrade( int exam, int grade ) { }
    public int getGrade( int exam ) { }
    public String getName() { }
} // CIS425_Student class

package edu.buffalostate.cis425.sp19.assignments.put-your-lastname-here; 

/* 
 * don't forget comments 
 */
public class CIS425_Course {
  public CIS425_Course( int capacity ) { }
  public boolean addStudent( String id, String name, int num_exams ) { }
  public CIS425_Student findStudent( String id ) { }
  public double computeAverage( int exam ) { }
  public static void main( String[] args ) { }
} // CIS425_Course class

package edu.buffalostate.cis425.sp19.assignments.put-your-lastname-here;  

/* 
 * don't forget comments 
 */
public class Student {
  private String id, name;

  // Constructor, set name of student
  public Student( String id, String name ) {
    this.setName(name);

    this.setID(id);

  }

  /**

   * set name of student

   * @param name string -- student name

   */

  public void setName(String name){

    this.name = name;

  }
  // return name of student
  public String getName() {
    return this.name;
  }
  // Add accessors to set the student ID and to get (return) the student ID

} // Student class

Answer 1

All the requirements have been satisfied.
Comment below if you have any doubts or require modifications..
Please do upvote the answer if it is helpful thanks...

Getter setter methods for ID field of Student class:

package HomeworkLib;

public class Student {

private String id, name;

// Constructor, set name of student

public Student(String id, String name) {

this.setName(name);

this.setID(id);

}

public void setID(String id) {

this.id = id;

}

public String getID() {

return this.id;

}

/*** set name of student * @param name string -- student name */

public void setName(String name) {

this.name = name;

}

// return name of student

public String getName() {

return this.name;

}

// Add accessors to set the student ID and to get (return) the student ID

} // Student class

Student implementation:

package HomeworkLib;

public class CIS425_Student extends Student {

int exams[];

int num_exams;

public CIS425_Student(String id, String name, int num_exams) {

super(id, name);

exams = new int[num_exams];//Creating array

this.num_exams = num_exams;//Svaed for error checking later

}

public boolean addGrade(int exam, int grade) {

if(exam < 0 || exam > num_exams) {//error checking

return false;

}

exams[exam] = grade;

return true;

}

public int getGrade(int exam) {

if(exam < 0 || exam > num_exams) {//error checking

return -1;

}

return exams[exam];

}

public String getName() {

return super.getName();//Calling super class method

}

} // CIS425_Student class

Course class:

package HomeworkLib;

public class CIS425_Course {

    int capacity;

    CIS425_Student roster[];

    int currIndex = 0;//to identify where to insert

    public CIS425_Course(int capacity) {

        this.capacity = capacity;

        roster = new CIS425_Student[capacity];

    }

    public boolean addStudent(String id, String name, int num_exams) {

        CIS425_Student student = new CIS425_Student(id, name, num_exams);

        if(currIndex < capacity) {//if room is there

            roster[currIndex] = student;

            currIndex++;

            return true;

        }

        return false;//No space

    }

    public CIS425_Student findStudent(String id) {

        for(int i = 0; i < currIndex; i++) {

            if(roster[i].getID().equalsIgnoreCase(id)) {//Student found

                return roster[i];

            }

        }

        return null;//No matchng records found

    }

    public double computeAverage(int exam) {

        int sum = 0;

        for(int i = 0; i < currIndex; i++) {

            sum += roster[i].getGrade(exam);

        }

        return sum / currIndex;

    }


    public static void main(String[] args) {

        CIS425_Course course = new CIS425_Course(2);

        course.addStudent("1", "Smarty", 2);

        course.addStudent("2", "Phailure", 2);

        course.findStudent("1").addGrade(1, 100);

        System.out.println("Sally Smarty has a grade of:"+ course.roster[0].getGrade(1)+" on exam 1 ");

        course.findStudent("2").addGrade(1, 60);

        System.out.println("Phil Phailure has a grade of:"+ course.roster[1].getGrade(1)+" on exam 1 ");

        System.out.println("Class average for exam 1: " + course.computeAverage(1));



    }

} // CIS425_Course class

Sample output: