Abstraktion ni nini katika OOP?

Question

Accepted Answer

**Abstraktion** inamaanisha kubaini *nini* kitu kinachofanya habari kuzihide *vipi* kinachofanya. Unaingiliana na kiolesura rahisi, thabiti na kuzaharibu utekelezaji ngumu nyuma yake.

## Nini dhidi ya vipi

```python
from abc import ABC, abstractmethod

class PaymentGateway(ABC):          # the abstraction: "what"
    @abstractmethod
    def charge(self, amount): ...    # callers only need this contract

class StripeGateway(PaymentGateway): # one "how"
    def charge(self, amount):
        # talk to Stripe's API, handle tokens, retries...
        return f"charged {amount} via Stripe"

class PayPalGateway(PaymentGateway): # another "how"
    def charge(self, amount):
        return f"charged {amount} via PayPal"

def checkout(gateway: PaymentGateway, amount):
    return gateway.charge(amount)    # depends only on the abstraction
```

`checkout` haiwezi kujua kamwe ikiwa ni Stripe au PayPal — inategemea *wazo* la kuchaji, si maelezo.

## Abstraktion dhidi ya enkapsulesheni

Zina uhusiano lakini tofauti: **enkapsulesheni** inahide hali ili kuiangalia; **abstraktion** inahide uchangamfu ili kurahisisha kiolesura. Enkapsulesheni ni kuhusu *kuzuia*; abstraktion ni kuhusu *nini cha kuonyesha*.

## Hatari

Abstraksheni yenye malezo (ambapo maelezo ya utekelezaji yanayotoka) na abstraksheni za mapema (zimejengwa kabla hauwezi kuelewa tatizo) zote zinaumiza. Jumuisha kile kinachobadilika kwa kawaida.

## Kwa nini inashangilia

Abstraktion ndilo jinsi unavyozuia uchangamfu: wanaita wafikiri kuhusu kiolesura kidogo badala ya mfumo mzima.

Inaruhusa kubadilisha utekelezaji — kuongeza mtoa huduma mpya wa malipo hugusa darasa moja, si kila mpigia simu — ambayo ni msingi wa kubuni sambamba, kubaini.