Creation of further objects

 1 public class Account {                      // Definition of class
 2     private double balance;                  // encapsulated attripbute (private)
 3 
 4     public double getBalance() {             // public definitions of methods (accessibla from everywhere)
 5         return balance;
 6     }
 7     public double transaction(double amount) {
 8         if (balance + amount >= 0) {        // Transaction is possible
 9             balance += amount;
10             return balance;
11         }
12         else                                // transaction impossible
13             return -1;                      // return of an error code
14     }
15 }

 1 public class Main {
 2 
 3     public static void main(String[] args) {
 4 
 5         Account account1 = new Account();  // Creation of object account1 of class Account
 6         account1.transaction(100);         // Invokation of method transaction() of object account1
 7 
 8         System.out.println("Balance: " + account1.getBalance());
 9     }
10 }