Question

///create a main menu to enter choices such as "Welcome to any college" then please enter your choice of information when you press a key 1. view students. 2. insert student 3. remove student 4. exit...and student ID#, age, birthday, location, expected gradation date

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 void addStudent(String student) {
// Automatically increases the array size
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){
//find the index of student
String [] b = new String[a.length-1];
students = a;
// int position = findStudent(student);
for (int i = 0,k=0; i < a.length;i++){
if (i == index){
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;
}



}
import java.util.Scanner;

public class d {
public static void main(String [] args){
CourseCOM666 com666 = new CourseCOM666("com666");
com666.addStudent("hank");
com666.addStudent("paul");
com666.addStudent("david");
com666.addStudent("ben");
com666.addStudent("jacob");

int sum = 0;
////////create a new array String students1[] to hold all students/////////////////////
String students1[] = com666.getStudents();

sum += com666.getNumberOfStudents();
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);

Scanner scan = new Scanner(System.in);
System.out.println("Enter the name of student and index:");
String student = scan.nextLine();
students1 = com666.addStudentByIndex(student,3);
com666.display(students1);

sum = com666.getNumberOfStudents();
System.out.println("After student was added the Student number is:" + sum);


System.out.println("remove 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("----------------------------");

//use do while loops

Answer 1

import java.util.Scanner;

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) {
                // Automatically increases the array size
                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){
        //find the index of student
        String [] b = new String[a.length-1];
        students = a;
        // int position = findStudent(student);
        for (int i = 0,k=0; i < a.length;i++){
                if (i == index){
                        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("hank");
                com666.addStudent("paul");
                com666.addStudent("david");
                com666.addStudent("ben");
                com666.addStudent("jacob");
                
                int sum = 0;
                ////////create a new array String students1[] to hold all students/////////////////////
                String students1[] = com666.getStudents();
                
                sum += com666.getNumberOfStudents();
                
                Scanner scan = new Scanner(System.in);
                
                
                
                
                
                //use do while loops
                int choice;
                
                do {
                        System.out.println("Welcome to any college");
                        System.out.println("1. View Student");
                        System.out.println("2. insert student");
                        System.out.println("3. remove student");
                        System.out.println("4. 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();
                                students1 = com666.addStudentByIndex(student,3);
                                com666.display(students1);
                                
                                sum = com666.getNumberOfStudents();
                                System.out.println("After student was added the Student number is:" + sum);
                        }
                        else if(choice == 3) {
                                System.out.println("remove 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("----------------------------");
                        }
                }while(choice!= 4);
                
        }
}