Menene polymorphism?

Question

IT Interview Practice · Accepted Answer

**Polymorphism** ("siffofi masu yawa") yana ba da dama ga wani dan tsari gida ya yi aiki tare da nau'ikan sankamakonon iri-iri. *Gaida daya* tana gudu *lambar daban-daba* dangane da ainihin abun da ake amfani - zabin a lokacin gudu. Wannan shi ne **polymorphism subtype**.

## Gaida daya, halayen da yawa

```java
class Animal { String speak() { return "..."; } }
class Dog extends Animal { String speak() { return "Woof"; } }
class Cat extends Animal { String speak() { return "Meow"; } }

Animal[] zoo = { new Dog(), new Cat() };
for (Animal a : zoo) {
    System.out.println(a.speak());   // Woof, then Meow
}                                    // same call, different result per type
```

Azumtsi yana kira `a.speak()` ba tare da dadi wanen dabbar ba - lokacin gudu yana rarraba zuwa daidai jujjuyawa.

## Me yasa ya kasance mai iko

Za ka iya ƙara sabuwar `Animal` subtype daga bari, kuma lupu a sama ake ci gaba da aiki tare da **sifili juyawa**. Lambar ta dogara ne a aji abun da ake amfani, ba bade aji ba.

```text
caller → Animal.speak()  ──dispatch──▶  Dog.speak()  OR  Cat.speak()
            (one interface)                  (many implementations)
```

## Haɗari

Kada ka rikitawa tare da overloading (suna daya, *sigogi* daban, wajen a lokacin kunenta). Gaskiya (subtype) polymorphism ana warware a *lokacin gudu* dangane da abun.

## Me yasa ya kasance mahimma

Polymorphism shine abin da ke ba da feishin gutsutsi: sabuwa halayen ya zo a matsayin sabuwa aji, ba a matsayin zane jaje a cikin `if/else` sarari.

Shi ne jigon da ke bayan Open/Closed Principle da gari-garin tsarin zane — ka yi programa zuwa wani dan tsari kuma ba da dama lokacin gudu fassarar za."},

Gaida daya, halayen da yawa

Me yasa ya kasance mai iko

Haɗari

Me yasa ya kasance mahimma

Tambayoyi masu alaƙa