import java.util.*;

    public class StudentApplication {

    Scanner input=new Scanner(System.in);
int index = 0;
public String[] id = new String[20];
public String[] name = new String[20];
public String[] marks = new String[20];
String Search = " ";
public static void main(String[]args){
StudentApplication app=new StudentApplication();
    app.choices();
    }
public void choices(){
System.out.println("1. Add Student record");
System.out.println("2. Delete Record");
System.out.println("3. Display Record");
System.out.println("4. Display All Records");
System.out.println("5. Exit");
try{
int choices;

System.out.print("Enter Your choice: ");
choices = input.nextInt();
if(choices == 1){
index = index + 1;
add();
choices();
}
    else if(choices == 2){
delete();
choices();
}

else if(choices == 3){
System.out.print("Enter an INDEX: ");
index = input.nextInt();
System.out.println("****View Record****");
System.out.println("ID: " + id[index]);
System.out.println("Name: " + name[index]);
System.out.println("Marks:" + marks[index]);
choices();
}

else if(choices == 4){

System.out.println("****View All Records****");
    for(int i=0;i<id.length;i++){
        if(id[i]!=null){
System.out.println(id[i]+"\t"+name[i]+"\t"+marks[i]);
        }
    }
choices();
}
    else if(choices == 5){
        System.exit(0);
    }    
else{
System.out.println("Program will now exit");
System.exit(0);
}
}
catch (Exception e){
System.out.print(e);
}
}
public void add(){
try{
    System.out.print("Enter ID: ");
id[index] = input.next();
System.out.print("Enter Name: ");
    name[index] = input.next();
    System.out.print("Enter marks: ");
marks[index] = input.next();
System.out.println("Data has been added!");
}
catch(Exception e){
System.out.print(e);
}
}
public void delete(){
try{
System.out.print("Enter index to delete data: ");
index = input.nextInt();
id[index] = null;
name[index] = null;
marks[index] = null;

index = 0;
System.out.println("Data has been deleted!");
choices();
}
catch(Exception e){
System.out.print(e);
}
}
    }