Agfdhyk

I'd like to create a console application, where there should be a possibility to create Objects while the program is running. My first attempts looked like this:

InputStreamReader isr = new InputStreamReader(System.in);

BufferedReader br = new BufferedReader(isr);

printMenu();

String input = br.readLine();

switch (input) {

    case "0":

        System.exit(0);

    case "1":

        createStudent();

(...)

createStudent():

String firstName;

String lastName;

InputStreamReader isr = new InputStreamReader(System.in);

BufferedReader br = new BufferedReader(isr);

String input = br.readLine();

System.out.println("whats your Lastname?");

input = br.readLine();

lastName = input;

System.out.println("and your Firstname?");

input = br.readLine();

firstName = input;

// Create Object with given attributes

Student unique = new Student(firstName,lastName);

The whole Application is based on user inputs. I need to be able to create multiple Students with diferent names (in my code the Name of the Object will always be "unique".

You need to use a collection to store your students! The most simple is an array:

Student students = new Student[100];

This will create an array for maximum 100 Students. One problem with this is that it cannot be resized, so if you add more then 100, new arrays need to be created, and copied which is not easy.

You should use a collection which has no fixed size: Any one from java.utils will do, like ArrayList, LinkedList, Stack, ...

LinkedList<Student> students = new LinkedList<Student>();

You will need to create an array list of Student objects. You could add an unlimited number of Student objects to the array list.

I played around with it a bit, and I figured out how to add objects to the ArrayList. Here is an example of how you could do this:

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.ArrayList;



public class Students {



    ArrayList<Student> unique = new ArrayList<Student>();



    public void createStudent() throws IOException {



        String firstName = "";

        String lastName = "";

        Student temp;



        InputStreamReader isr = new InputStreamReader(System.in);

        BufferedReader br = new BufferedReader(isr);



        System.out.println("whats your Lastname?");

        lastName = br.readLine();



        System.out.println("and your Firstname?");

        firstName = br.readLine();



        // Create Object with given attributes

        temp = new Student(firstName, lastName);

        unique.add(temp);

    }



    public String getFirstName(int index) {

        return unique.get(index).firstName;

    }



    public String getLastName(int index) {

        return unique.get(index).lastName;

    }



    public static void main(String args) throws IOException {



        Students students = new Students();

        students.createStudent();



        System.out.println(students.getFirstName(0));

        System.out.println(students.getLastName(0));

    }

}



class Student {



    String firstName = "";

    String lastName = "";



    public Student(String fn, String ln) {

        firstName = fn;

        lastName = ln;

    }

}

Let me know if you need any more help.