Object ,Class and Methods in java

class Bank {
  public static void main (String[] args) {
    // Creates an object with the class Bank_Account defined below
    Bank_Account account = new Bank_Account(150.00);
    System.out.println ("Balance: "+ account.current_Account());
    account.debit_Account(50.30);
    System.out.println ("New Balance : "+ account.current_Account());
  }
}

class Bank_Account {
  private double value_account;
  public Bank_Account ( double initial_value) {
    value_account = initial_value;
  } // end constructor for object creation
  public void debit_Account ( double number) {
    value_account = value_account + number;        
  }
  public double current_Account () {
    return value_account;
  }
}