Menene kaura da hade?

Question

Accepted Answer

**Kaura** tana auna kaina wace aji wani modulu ya dogara da wani; **hade** tana auna kaina wace aji abubuwa *jiya* modulu suke hade tare. Burin: **kaura kaifi, hade babbar**.

## Me yasa ya isa

```text
HIGH cohesion  → a class does ONE well-defined job, parts relate strongly  ✅
LOW  coupling  → modules interact through small, stable interfaces         ✅
```

## Hade kaifi (mummuna) kaida hade babbar (kyau)

```python
# LOW cohesion: unrelated responsibilities jammed together
class Utils:
    def parse_csv(self, s): ...
    def send_email(self, to): ...
    def hash_password(self, p): ...   # nothing in common

# HIGH cohesion: each class has a single, focused purpose
class CsvParser:     ...
class Mailer:        ...
class PasswordHasher: ...
```

## Kaura yana da iko kaida kaura bauwa

```python
# TIGHT: OrderService is welded to a concrete class
class OrderService:
    def __init__(self):
        self.db = MySqlDatabase()        # can't swap or test in isolation

# LOOSE: depends on an abstraction, injected in
class OrderService:
    def __init__(self, db: Database):    # any Database works
        self.db = db
```

Kaura bauwa ta ba ka damar maye `MySqlDatabase` tare da ita gyarmin a kan aru don gwaje, tare da babu sashe zuwa `OrderService`.

## Me yasa ya isa

Kaura yana da iko shine abin da ya sa jinkari "yakada" — taɓa jama'a daya da goma kuma suka karye; kaura bauwa ta ɗauke jinkari zuwa tushe.

Hade babbar yana ba da damar nemo lambar da za a gwaje: idan jama'a yana yin abin daya kawai, ka sani cina gida halayen kuma abin da gwaji ya tokaci.

Wanan awo masu auna gida ciki ga kusan dukan dokoki na tsarakawa.