Paano JavaScript ke sarrafa alaƙa da paano akwai sakamako?

Question

Accepted Answer

JavaScript yana amfani da **jujuwa jujuwa watacciyya**. Marubuta yana amfani da algorithm na **alamomi-da-sauka**: farawa daga tushe (abin sadarwa na jiya, gajerun amfani da yau), yana alamar duk abin **da za a iya isa gida**, sannan yana sake komai abin **da ba za a iya isa gida ba**. Ba ka `free()` kai tsaye ba kaikayi — amma *zai yiwu* ka ajiye tunani ta hanyar karewa, yana haifar da sakamako.

## Hudu sakamako-tushe na gida

```js
// 1. Unbounded globals / caches that never shrink
window.cache = window.cache || {};
window.cache[id] = bigObject; // grows forever

// 2. Forgotten event listeners
el.addEventListener("click", handler);
// must call el.removeEventListener("click", handler) when done

// 3. Forgotten timers
const id = setInterval(tick, 1000);
// must clearInterval(id)

// 4. Closures capturing large objects longer than needed
function outer() {
  const huge = new Array(1e6);
  return () => huge.length; // keeps `huge` alive as long as the closure lives
}
```

Sanye daga wani wuri da ya isa gida (jiya, mai sauraron ifiya, rufaffiyar aiki, noda DOM da aka daina shekara da ma sauye-sauyewa a cikin JavaScript) yana ci diba da kayan abin sadarwa daga jujuwa.

## Binciken sakamako

```js
performance.memory; // rough heap size (Chrome)
// Chrome DevTools → Memory → take heap snapshots at two points and compare
```

Dauki zakoki na yayin saka kafin/bayan aikin; sauye da ke haɓaka "adadi da aka kiyaye" yana nuna abin da ba a sallame ba.

## Kayan aikiy don kawar da taƙin abubuwa

```js
const meta = new WeakMap(); // keys are weakly held — GC can collect them
meta.set(domNode, data);    // doesn't prevent domNode from being garbage-collected
```

## Kayi mahalaci

Apps masu dogon lokaci (SPAs, garaje Node) suna rushe ko jajirtawa daga sakamako.

Warkawar shine tsattsauran tsattsauran fage — bugi mai sauraro/lokuta, takaici na tacizon (LRU), kawar da sauya kewaya, da kuma yi amfani da `WeakMap`/`WeakSet` don metadata wanda sai ya kasance jari kasuwa.