CODEWITHSUNDEEP
c#ooprefactoring
user5848956
user5848956

Reputation:

How to extract method from its class in order to reused it in many places and keep encapsulation?

I'm writing ATM software in order to train object-oriented programming and I have got Pin class with a VerifyPin method. 

    class Pin
{
    private int _pin;

    public void ChangePin (int newPin)
    {
        if (newPin.ToString().Length != 4)
        {
            throw new ArgumentException("PIN must be exactly 4 digits long");
        }

        _pin = newPin;
    }

    public bool VerifyPin (int pin)
    {
        return (_pin == pin);
    }


}

I'm trying to call this method inside other classes in order to verify PIN which is stored inside Card, as well as Account.

So far I came up with an idea to do something like this, but I'm sure there is a better way

    class Card
{
    private Pin _pin;

    public Card(Pin pin)
    {
        this._pin = pin;   

    public bool VerifyPin (int pin)
    {
        return this._pin.VerifyPin(pin);
    }
}

Any sources to learn more about subject will be welcomed as well.

Upvotes: 1

Views: 100

Answers (3)

kristianp
kristianp

Reputation: 5895

I would say that the pin should be encapsulated in an Account, but not a Card. A card would be associated with an account. So to verify a pin when given a card you would call the following code:

bool verified = myCard.Account.VerifyPin(pin);

(A static method doesn't work because it can't access the field _pin).

Upvotes: 0

user5326354
user5326354

Reputation:

This method can be made static. This way it could be accessed and used from any class in the same project, But seems what you would like to create a pin object and then call that object method : VerifyPin that will take the pin you want to validate as parameter

Upvotes: 2

Erik Karlstrand
Erik Karlstrand

Reputation: 1537

If you make the VerifyPin method static you may call it without creating an instance of the Pin class.

public static bool VerifyPin(int pin){}

Pin.VerifyPin(pin);

Upvotes: 0

Related Questions