X'inhuma l-operaturi spread u rest?

Question

Accepted Answer

Tnejn jużżaw `...` imma f'**direzzjonijiet opposti**: spread **jespandi** kolettur f'items individwali; rest **iġbor** items f'singola array/objett.

## Spread — espandi

```js
const a = [1, 2], b = [3, 4];
const merged = [...a, ...b];          // [1, 2, 3, 4]
const copy = [...a];                   // shallow copy
const obj = { ...user, active: true }; // copy object + override/add a field
Math.max(...[1, 5, 3]);                // 5 — spread array into arguments
```

## Rest — iġbor

```js
function sum(...nums) {     // gather all args into an array
  return nums.reduce((a, n) => a + n, 0);
}
sum(1, 2, 3);               // 6

const [first, ...others] = [10, 20, 30]; // first=10, others=[20, 30]
const { id, ...rest } = user;            // pull out id, keep the rest
```

## Dettalj kruċjali: spread hija SHALLOW copy

```js
const original = { user: { name: "Ann" } };
const copy = { ...original };
copy.user.name = "Bob"; // ⚠️ also changes original.user.name — nested object is SHARED
```

Spread tnisl biss il-livell ta' fuq; objekti nested xorta huma referenzi maqsuma. Għal aġġornamenti ta' stat, normalment nbiddel biss il-livell ta' fuq, li huwa tajjeb, imma kun affettwat għal strutturi profundi.

## Għaliex importanti

Spread hija l-mod standard biex tagħmel **immutable updates** (copy + nbiddel) f'React/Redux, u rest jagħmel funzjonijiet variadici u destructuring "ħu l-bqija" nadif.