Question

----fix code to search and delete a student by Identification number

import java.util.Scanner;

public class COurseCom666 {

    private String courseName;
    private String[] students = new String[1];
    private int numberOfStudents;

    public COurseCom666(String courseName) {
        this.courseName = courseName;
    }

    public String[] getStudents() {
        return students;
    }

    public int getNumberOfStudents() {
        return numberOfStudents;
    }

    public String getCourseName() {
        return courseName;
    }

    public int DeleteStudentsByID() {
        return deleteStudentByID();
    }

    public void addStudent(String student) {

        if (numberOfStudents == students.length) {
            String[] a = new String[students.length + 1];
            for (int i = 0; i < numberOfStudents; i++) {
                a[i] = students[i];
            }
            students = a;
        }
        students[numberOfStudents] = student;
        numberOfStudents++;
    }

    public String[] addStudentByIndex(String student, int index) {
        String[] a = new String[students.length + 1];
        if (numberOfStudents == students.length) {
            for (int i = 0; i < a.length; i++) {
                if (i < index) {
                    a[i] = students[i];
                } else if (i == index) {
                    a[i] = student;
                } else {
                    a[i] = students[i - 1];
                }
            }
        }
        numberOfStudents++;
        return a;
    }

    public static void display(String[] students) {
        System.out.println("========================");
        System.out.print("Now the New students Array is : \n");
        for (int i = 0; i < students.length; i++) {
            System.out.println("Index: " + (i) + "--> " + students[i] + " ");
        }
    }

    public String[] removeStudentByIndex(String[] a, int index) {

        String[] b = new String[a.length - 1];
        students = a;

        for (int i = 0, k = 0; i < a.length; i++) {
            if (i == index) {
                continue;
            } else {
                b[k++] = a[i];
            }
        }
        numberOfStudents--;
        return b;

    }

    public int[] deleteStudentByID(int num[]) {

    }


    private int findStudent(String student) {
        for (int i = 0; i < numberOfStudents; i++) {
            if (students[i].equals(student)) {
                return i;
            }
        }
        return -1;
    }
}

import java.util.Scanner;

public class d {

    public static void main(String[] args)
    {
        COurseCom666 com666 = new COurseCom666("com666");
        com666.addStudent("Bishal");
        com666.addStudent("Ana");
        com666.addStudent("Ying");
        com666.addStudent("Samuel");
        com666.addStudent("Surai");
        int sum = 0;

        String students1[] = com666.getStudents();
        sum += com666.getNumberOfStudents();
        Scanner scan = new Scanner(System.in);

        int choice;

        do {
            System.out.println("Welcome to St.Joseph's College");
            System.out.println("1. View Student");
            System.out.println("2. Insert Student");
            System.out.println("3. Remove a student");
            System.out.println("4. Delete a student by ID");
            System.out.println("5. Exit");
            choice = scan.nextInt();
            if (choice == 1)
            {
                for (int i = 0; i < students1.length; i++)
                {
                    System.out.println("Index is: " + (i) + "---> " + students1[i]);
                }
                System.out.println("Number of students attending the Course is: " + sum);
            }
            else if (choice == 2)
            {
                System.out.println("Enter the name of student and index: ");
                scan.nextLine();
                String student = scan.nextLine();
                int index = scan.nextInt();
                students1 = com210.addStudentByIndex(student, 3);
                com666.display(students1);
                sum = com666.getNumberOfStudents();
                System.out.println("After student was added number is: " + sum);
            }
            else if (choice == 3) {
                System.out.println("Remove a student by index");
                int index = scan.nextInt();
                students1 = com666.removeStudentByIndex(students1, index);
                com666.display(students1);
                sum = com666.getNumberOfStudents();
                System.out.println("After student drop number is: " + sum);
                System.out.println("Number of students attending the Course is: " + sum);
                System.out.println("----------------------------------");
            }
            else if (choice ==4) {
                System.out.println("Delete a students ID");

                System.out.println("Bishal", StudentID);
                String student1_name = "Bishal";
                int StudentID = 111111;

                System.out.println("Ana", StudentID);
                String student2_name = "Ana";
                int StudentID = 222222;


                String student3_name = "Ying";
                int StudentID = 333333;

                String student4_name = "Samuel";
                int student4_id = 444444;

                String student5_name = "Surai";
                int student5_id = 555555;



            }


        }
        while (choice!= 5);
    }
}

Answer 1

This is the code to fix search and delete student by identification number and I also mention the comment in the code to easily understand the changes, just copy the code and paste it on any java ide or complier.

import java.util.*;

class COurseCom666 {

private String courseName;
private String[] students = new String[1];
private int numberOfStudents;

public COurseCom666(String courseName) {
this.courseName = courseName;
}

public String[] getStudents() {
return students;
}

public int getNumberOfStudents() {
return numberOfStudents;
}

public String getCourseName() {
return courseName;
}

public void addStudent(String student) {

if (numberOfStudents == students.length) {
String[] a = new String[students.length + 1];
for (int i = 0; i < numberOfStudents; i++) {
a[i] = students[i];
}
students = a;
}
students[numberOfStudents] = student;
numberOfStudents++;
}

public String[] addStudentByIndex(String student, int index) {
String[] a = new String[students.length + 1];
for (int i = 0; i < a.length; i++) {
if (i < index) {
a[i] = students[i];
} else if (i == index) {
a[i] = student;
} else {
a[i] = students[i-1];
}
}
numberOfStudents++;
return a;
}

public static void display(String[] students) {
System.out.println("========================");
System.out.print("Now the New students Array is : \n");
for (int i = 0; i < students.length; i++) {
System.out.println("Index: " + (i) + "--> " + students[i] + " ");
}
}

public String[] removeStudentByIndex(String[] a, int index) {

String[] b = new String[a.length - 1];
students = a;

for (int i = 0, k = 0; i < a.length; i++) {
if (i == index) {
continue;
} else {
b[k++] = a[i];
}
}
numberOfStudents--;
return b;

}
// fix the code
public String[] deleteStudentByID(String a[],int id) {
String sname[]={"Bishal", "Ana","Ying","Samuel","Surai"};
int StudentID[]={111111,222222,333333,444444,555555};
int index=0;
String name="";
// find name of student we want to delete by id
for(int i=0;i<StudentID.length;i++){
if(StudentID[i]==id){
index=StudentID[i];
name=sname[i];
break;
}
}
String[] b = new String[a.length - 1];
students = a;

for (int i = 0, k = 0; i < a.length; i++) {
if (a[i].equals(name)) {
continue;
} else {
b[k++] = a[i];
}
}
numberOfStudents--;
return b;
}

private int findStudent(String student) {
for (int i = 0; i < numberOfStudents; i++) {
if (students[i].equals(student)) {
return i;
}
}
return -1;
}
}

public class d{

public static void main(String[] args)
{
COurseCom666 com666 = new COurseCom666("com666");
com666.addStudent("Bishal");
com666.addStudent("Ana");
com666.addStudent("Ying");
com666.addStudent("Samuel");
com666.addStudent("Surai");
int sum = 0;

String students1[] = com666.getStudents();
sum += com666.getNumberOfStudents();
Scanner scan = new Scanner(System.in);

int choice;

do {
System.out.println("Welcome to St.Joseph's College");
System.out.println("1. View Student");
System.out.println("2. Insert Student");
System.out.println("3. Remove a student");
System.out.println("4. Delete a student by ID");
System.out.println("5. Exit");
choice = scan.nextInt();
if (choice == 1)
{
for (int i = 0; i < students1.length; i++)
{
System.out.println("Index is: " + (i) + "---> " + students1[i]);
}
System.out.println("Number of students attending the Course is: " + sum);
}
else if (choice == 2)
{
System.out.println("Enter the name of student and index: ");
scan.nextLine();
String student = scan.nextLine();
int index = scan.nextInt();
students1 = com666.addStudentByIndex(student, 3);
com666.display(students1);
sum = com666.getNumberOfStudents();
System.out.println("After student was added number is: " + sum);
}
else if (choice == 3) {
System.out.println("Remove a student by index");
int index = scan.nextInt();
students1 = com666.removeStudentByIndex(students1, index);
com666.display(students1);
sum = com666.getNumberOfStudents();
System.out.println("After student drop number is: " + sum);
System.out.println("Number of students attending the Course is: " + sum);
System.out.println("----------------------------------");
}
else if (choice ==4) {
System.out.println("Delete a students ID");
String name[]={"Bishal", "Ana","Ying","Samuel","Surai"};
int StudentID[]={111111,222222,333333,444444,555555};
  
for(int i=0;i<name.length;i++)
System.out.println(name[i]+" "+StudentID[i]);
  
// take id from user that we want to delete
int id=scan.nextInt();

students1 = com666.deleteStudentByID(students1,id);
com666.display(students1);
sum = com666.getNumberOfStudents();
System.out.println("After student drop number is: " + sum);
}
}
while (choice!= 5);
}
}