JAVA program to entry student details and check wether pass/fail using array of objects !!! a new thing indeed !!! a chotamota software

import java.util.*;
public class ArrayObjects{
    String name;//important
    int age,std;
    double eng,maths,phy,chem,bio;
    static Scanner sc=new Scanner(System.in);
    /**
     * This is the monitor of the class...
     *
     * @param args A parameter
     */
    public static void main(String []args){
        System.out.println("Enter the number of students");
        int n=sc.nextInt();
        System.out.println("1:Accept details\n2:Display all records\n3:Display rool no. wise\n4:Deleting records\n5:Modify details\n6:Display wether pass or fail");
        ArrayObjects []ob=new ArrayObjects[n];
        int ch=0;
        do{
            System.out.println("....Enter choice....");
            ch=sc.nextInt();
            switch(ch){
                case 1:for(int i=0;i<n;i++){
                            ob[i]=new ArrayObjects();
                            ob[i].getdetails();
                        }
                        break;
                case 2:for(int i=0;i<n;i++){
                            ob[i].dispdetails(i);
                        }
                        break;
                case 3:System.out.println("Enter the roll number you want to search");
                       int rollnum=sc.nextInt();
                        for(int i=0;i<n;i++){
                            if((i+1)==rollnum)
                            ob[i].dispdetails(i);
                        }
                        break;
                case 4:System.out.println("Enter the roll number you want to delete");
                       int delroll=sc.nextInt();
                        for(int i=0;i<n;i++){
                            if((i+1)==delroll)
                            ob[i].deldetails();
                        }
                        break;
                       
                case 5:System.out.println("Enter the roll number of student to modify");
                       int modroll=sc.nextInt();
                       for(int i=0;i<n;i++){
                            if((i+1)==modroll)
                            ob[i].getdetails();
                        }
                        break;
                case 6:for(int i=0;i<n;i++){
                            ob[i].reportcard();
                        }
                        break;
                default:System.out.println("You have entered wrong choice Sir/Madam pls try again !");
                        break;
                    }
                }while(ch>0);
            }
    /**
     * This method accepts details of students
     *
     */
    public void getdetails(){
        System.out.println("Enter the student's name");
        name=sc.next();
        System.out.println("Enter the student's age");
        age=sc.nextInt();
        System.out.println("Enter the student's class/standard");
        std=sc.nextInt();
        System.out.println("Enter the student's English marks");
        eng=sc.nextDouble();
        System.out.println("Enter the student's Maths marks(out of 100)");
        maths=sc.nextDouble();
        System.out.println("Enter the student's Physics marks(out of 100)");
        phy=sc.nextDouble();
        System.out.println("Enter the student's Chemistry marks(out of 100)");
        chem=sc.nextDouble();
        System.out.println("Enter the student's Biology marks(out of 100)");
        bio=sc.nextDouble();
    }
    /**
     * This method displays details of the students
     *
     * biodata
     */
    public void dispdetails(int roll){
         if(name==null){
          roll=0;
          System.out.println();
          System.out.println("Student's name: "+name);
          System.out.println("Students age: "+age);
          System.out.println("Students roll number: "+roll);
          System.out.println("Students standard: "+std);
          System.out.println("Students English marks: "+eng);
          System.out.println("Students Mathematics marks: "+maths);
          System.out.println("Students Physics marks: "+phy);
          System.out.println("Students Chemistry marks: "+chem);
          System.out.println("Students Biology marks: "+bio);
         }
         else{
         System.out.println();
         System.out.println("Student's name: "+name);
         System.out.println("Students age: "+age);
         System.out.println("Students roll number: "+(roll+1));
         System.out.println("Students standard: "+std);
         System.out.println("Students English marks: "+eng);
         System.out.println("Students Mathematics marks: "+maths);
         System.out.println("Students Physics marks: "+phy);
         System.out.println("Students Chemistry marks: "+chem);
         System.out.println("Students Biology marks: "+bio);
       }
    }
    /**
     * This method deletes students entry as per entered roll number
     *
     */
    public void deldetails(){
        name=null;
        age=0;
        std=0;
        eng=0;
        maths=0;
        phy=0;
        chem=0;
        bio=0;
        System.out.println("...Your respected record hasbeen deleted...");
    }
   
    /**
     * This method analyzes whether student have passed or failed
     *
     *
     */
    public void reportcard(){
        double avg=(eng+maths+phy+chem+bio)/5;
        if(avg>40.0 && eng>40.0 && maths>40.0 && phy>40.0)
        System.out.println(name+" has passed");
        else if(avg>40.0 && eng>40.0 && maths>40.0 && bio>40.0)
        System.out.println(name+" has passed");
        else if(avg>40.0 && eng>40.0 && maths>40.0 && chem>40.0)
        System.out.println(name+"has passed");
        else if(avg>40.0 && eng>40.0 && chem>40.0 && bio>40.0)
        System.out.println(name+" has passed");
        else if(avg>40.0 && eng>40.0 && phy>40.0 && bio>40.0)
        System.out.println(name+" has passed");
        else if(avg>40.0 && eng>40.0 && phy>40.0 && chem>40.0)
        System.out.println(name+" has passed");
        else
        System.out.println(name+" has failed");
    }
}
      
give reply as well !!!!