student.java file
package com.company;  public class Student {     String name;     String email;     int age;     double grade; }
main.java file
package com.company; import java.util.ArrayList; import java.util.Scanner; public class Main {     public static void main(String[] args) {          Scanner input = new Scanner(System.in);         ArrayList<Student> students_arraylist = new ArrayList();        // int loop1 = 0;         String loop;         do {             Student student_object = new Student();             System.out.println("Enter\n1 to add\n2 to Update \n3 to Search \n4 to remove \n5 to Print");             int option = input.nextInt();          //   int index1;             switch (option) {                 case 1:                     // to add new student                     System.out.println("Enter 1 to add \n 2 to add in specific index");                     int add_option = input.nextInt();                     if (add_option == 1) {                         System.out.println("enter name of student ");                         student_object.name = input.next();                         System.out.println("enter age of student ");                         student_object.age = input.nextInt();                         System.out.println("enter email of student ");                         student_object.email = input.next();                         System.out.println("enter grade of student ");                         student_object.grade = input.nextDouble();                         students_arraylist.add(student_object);                     } else if (add_option == 2) {                         System.out.println("Enter Strudent Index");                         int index1 = input.nextInt();                         System.out.println("Enter Strudent Name");                         student_object.name = input.next();                         System.out.println("Enter Strudent Age");                         student_object.age = input.nextInt();                         System.out.println("Enter Strudent Email");                         student_object.email = input.next();                         //students_arraylist.add(index,student_object);                         System.out.println("enter grade of student ");                         student_object.grade = input.nextDouble();                         students_arraylist.add(index1, student_object);                         }else {                         System.out.println("error");                     }                     break;                // System.out.println("Enter 1 to add new Student ");                 case 2:                     // to update name of student in specific index with newName                     System.out.println("Enter new name ");                    // String newName = input.next();                     student_object.name = input.next();                     System.out.println("enter index ");                     int index1 = input.nextInt();                     students_arraylist.set(index1, student_object);                     break;                 case 3:                     // Searching                     System.out.println("Enter Search Name");                     String Search_name = input.next();                     for (int i = 0; i < students_arraylist.size(); i++) {                         if (students_arraylist.get(i).equals(Search_name)) {                             System.out.println("index of " + i);                             break;                             //break; -> when found name -> out of loop                         }                     }                     break;                 case 4:                     // to remove student                     System.out.println("Enter 1 to remove with name \n 2 to remove with index");                     int remove_option = input.nextInt();                     if (remove_option == 1) {                         // remove student by name                         System.out.println("enter remove name ");                     //    int removename = input.next();                       //  Student.remove(removename);                     } else if (remove_option == 2) {                         //remove student by index                         System.out.println("enter remove index");                     //    int removeindex = input.nextInt();                        // student_object.remove(removeindex);                     } else {                         System.out.println("error");                     }                     break;                 case 5:                     // to print all data from arrayList                     for (int i = 0; i <  students_arraylist.size(); i++) {                         System.out.println("Student name= " +  students_arraylist.get(i));                     }                      break;          //  break;             default:                 System.out.println("ERROR");             }             System.out.println("Enter Yes to Repeat ");             loop = input.next();         } while (loop.equals("yes")) ;                // System.out.println("error");          }     } //}