ATM.java

import java.util.*;

public class ATM{
    public static void main(String[] args) {
        ATMop obj = new ATMop();
    }
}
class Data{
    float balance;
}
class ATMop{
    //float balance;
     Scanner sc = new Scanner(System.in);
     HashMap <Integer,Data> map=new HashMap<>();
    ATMop(){
        System.out.println("*************************************************");
        System.out.println("Welcome to our ATM");
        op();
    }
    public void op(){
        System.out.println("*************************************************");
        System.out.println("Enter valid pin:");
        int pincode = sc.nextInt();
        if((map.containsKey(pincode))==true){
            Data obj = map.get(pincode);
            menu(obj);  
        }
        else{
            System.out.println("*************************************************");
            System.out.println("Please create your account first");
            System.out.println("Set up your pincode:");
            int pin = sc.nextInt();
            Data obj = new Data();
            map.put(pin , obj);
             menu(obj);
        }
    }
    
    public void menu(Data obj){
        System.out.println("*************************************************");
        System.out.println("Please enter your choice:");
        System.out.println("1.Check Balance");
        System.out.println("2. Deposit Money");
        System.out.println("3.Withdraw Money");
        System.out.println("4.Check another account");
        System.out.println("5.Exit");

        int x = sc.nextInt();
        if(x==1){
            check_balance(obj);
        }
        else if(x==2){
            deposit(obj);
        }
        else if(x==3){
            withdraw(obj);
        }
        else if(x==4){
           op();
        }
        else if(x==5){
           System.out.println("Thank You!");
        }
        else{
            System.out.println("Please enter a valid number");
            menu(obj);
        }
    }
public void check_balance(Data obj){
    System.out.println("*************************************************");
    System.out.println("Your Balance:"+obj.balance);
     menu(obj); 
}

public void deposit(Data obj){
    System.out.println("*************************************************");
    System.out.println("Enter your amount:");
    float a = sc.nextFloat();
    obj.balance= obj.balance + a;
    System.out.println("Amount deposited successfully!");
     menu(obj); 
}
public void withdraw(Data obj){
    System.out.println("*************************************************");
    System.out.println("Enter your amount:");
    float a = sc.nextFloat();
    if(obj.balance >= a){
   obj.balance= obj.balance - a;
    System.out.println("Amount withdrawn successfully!");
    }
    else{
        System.out.println("Insufficient balance");
    }
     menu(obj); 
}
}