Hotel booking system container class

Question

1.A method which traverses the array and instantiates a default Room object referenced by each array cell. From this point onwards, we will assume that each room in the hotel has a number which is the same as its index in the array - room number 6 will be in cell 6 of the array, etc.
2.A method which accepts an integer argument representing a room number and returns a reference to the Room object in that cell of the array. If the argument is illegal, a null reference should be returned. Call this method �getRoom�.
how to get these

Answer 1

//Room.java
public class Room{
    //room instance vars here
    public Room(){
        //put defalut values in instance vars
    //access methods to instance vars
    public String toString(){
        //return meaningful name
//RoomManager.java
public class RoomManager{
    private static RoomManager me = new RoomManager();
    private static final int NUM_ROOMS = 20;
    private Room[] rooms = new Room[NUM_ROOMS];
    public static RoomManager instance(){
        return me;
    private RoomManager(){
        for(int i=0;i<NUM_ROOMS;i++)rooms[i] = new Room();
    public Room getRoom(int no){
        if((no<0)||(no>=NUM_ROOMS))return null;
        return rooms[no];
//So in any part of your code you need access to a room via room no you do
Room room1 = RoomManager.instance().getRoom(1);