Menene traits kuma yaushe suke amfani da su?

Question

IT Interview Practice · Accepted Answer

**Trait** wata hanya ce ta **sake amfani da lambar a cikin azuzuwan da yawa** waɗanda ba su da alaƙa ta gida. Tun da PHP yana ba da damar gida gida kawai, traits suna ba da hanya ta raba hanyoyi (da kaddarori) a tsaye — wata nau'i na "ƙirar" sake amfani da lambar, kamar mixins.

## Matsalar da traits ke warwarewa

```text
PHP has single inheritance — a class can extend only ONE parent. But you often want
to share the SAME methods across unrelated classes (e.g. logging, timestamps).
Duplicating the code is bad; traits let you reuse it without inheritance.
```

## Siffanta da amfani da trait

```php
<?php
trait Timestampable {
    private ?DateTime $createdAt = null;

public function setCreatedAt(): void {
        $this->createdAt = new DateTime();
    }
    public function getCreatedAt(): ?DateTime {
        return $this->createdAt;
    }
}

trait Loggable {
    public function log(string $msg): void {
        echo "[" . static::class . "] $msg";
    }
}

// a class can USE MULTIPLE traits — their methods become part of the class
class Article {
    use Timestampable, Loggable;     // mix in BOTH traits' methods
}

$a = new Article();
$a->setCreatedAt();    // from Timestampable
$a->log("created");     // from Loggable
```

Trait jerin hanyoyi/kaddarori ne. Azuzu `use` ɗaya ko fiye da traits don **haɗa** manyan su — samun aiki ba tare da gida daga kakakin gida gida ba.

## Traits vs gida vs interfaces

```text
Inheritance (extends) → single parent, "is-a", inherits implementation
Interface → a CONTRACT (signatures only, no code), multiple allowed
Trait → reusable IMPLEMENTATION (actual code), multiple allowed, NO contract
→ Interfaces say WHAT a class can do; traits provide HOW (shared code).
  They're often used together: implement an interface, use a trait for the impl.
```

## Warwarewa wa gida

```php
class X {
    use TraitA, TraitB {
        TraitA::hello insteadof TraitB;   // if both define hello(), pick TraitA's
        TraitB::hello as helloB;           // alias TraitB's version
    }
}
```

Idan traits biyu suka siffanta hanya gida, PHP yana buƙatar ka warware gida kai tsaye.

## Menene dalili yana da mahimmanci

Traits sune mahimman aikin PHP don **sake amfani da lambar a cikin azuzuwan da ba su da alaƙa ba**, warware ainihi takaitawa: tun da PHP yana ba da damar gida gida kawai, traits suna ba da sake amfani a tsaye (mixins) don raba aiki gida — logging, timestamps, soft-deletes, taimakon serialization — a cikin azuzuwan da ba su raba kakakin gida.

Ganin su yana da mahimmanci saboda ana amfani da su sosai a cikin PHP frameworks (Eloquent na Laravel yana amfani da traits sosai don halaye na model kamar `SoftDeletes`, `HasFactory`), saboda haka zaka ci karo dasu akai-akai.

Sanin yadda traits ya bambanta da gida (sake amfani ba tare da "is-a" alaƙa ba) da interfaces (traits suna ba da ainihi *aiki*/lambar, daddauki interfaces ƙayyadaddun *alkawari*/sigishi - kuma biyu ana haɗe da su akai-akai: interface yana bayyana iya, trait yana ba da aiki gida) yana muhimmi don amfani su daidai.

Traits suna ba da DRY da ƙirar design da gida kawai ba zai iya, ƙaura da su ga kudi gida da akai-akai sanin don rubutu lambar PHP wanda zai karɓa da fahimtar frameworks da aka gina koli su. (Gargadi: amfani da traits da yawa zai iya ba da duhun inda wayar ta fito, saboda haka amfani da su don ainihi gida-ƙata sake amfani, ba a matsayin baje.)

Matsalar da traits ke warwarewa

Siffanta da amfani da trait

Traits vs gida vs interfaces

Warwarewa wa gida

Menene dalili yana da mahimmanci

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