Arrow functions su nawa suke bambanta da aiki na yau-yau?

Question

Accepted Answer

Arrow functions sun fi gajeriya, amma bambance-bambancar gaske sun kasance a cikin **halin ɗaukar `this`**, ba kawai sako ba.

```js
const regular = function () {};
const arrow = () => {};
const short = x => x * 2; // implicit return for one expression
```

## Bambance-bambancar mahimmanci

**1. Babu nasu `this`** — arrows suna gida `this` daga wuri da ke kewaye. Wannan shine bambance-bambancen da ya fi mahimmanci da dalilin da ya sa suke kyau domin calls na bago:

```js
const timer = {
  seconds: 0,
  start() {
    setInterval(() => this.seconds++, 1000); // ✅ `this` is timer
    // a regular function here would have its own `this` (undefined) → bug
  },
};
```

**2. Babu `arguments` object** — yi amfani da rest parameters a maimakon haka:

```js
const sum = (...args) => args.reduce((a, b) => a + b, 0);
```

**3. Ba a iya amfani da su a matsayin masu ba — `new arrow()` yana jefa, kuma babu `prototype` nasu.

## Lokacin da ba a yi amfani da arrow

```js
const obj = {
  name: "Ann",
  greet: () => `Hi ${this.name}`, // ❌ `this` is NOT obj (it's outer scope)
  greet2() { return `Hi ${this.name}`; }, // ✅ method needs dynamic `this`
};
```

Kad ba a yi amfani da arrows domin **hanyoyin aiki na object** (ba za su ɗauki object ba) ko lokacin da kana buƙatar dynamic `this`/`arguments` (event handlers da ke dogara da `this` kasua abin da aka maimaita).

## Me ya sa haka ya mahimmanci

Yi amfani da arrows domin calls na bago da gajeriya aiki inda neman `this` shine abin da kuke so; yi amfani da aiki na yau-yau domin hanyoyin, masu ba, da hanyoyin prototype.