Menene spreead da rest operators?

Question

Accepted Answer

Duka suna amfani da `...` amma a **akasin jiya**: spread **fadada** tari zuwa abubuwan da suka dace; rest **tara** abubuwan zuwa tsari guda/hoto.

## Spread — fadada

```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 — tara

```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
```

## Muhimmin bayanai: spread shine kafe SHALLOW

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

Spread yana kafi kawai matakin sama; abubuwan da suka makali har yanzu ana raba rujukan. Don sabuntawa jihar zaka yawanci canja matakin sama kawai, wanda ya kyau, amma sannu waje ga tsarin zurfawa.

## Me yake matukar mahimmanci

Spread shine hanya ta daidai don yi **immutable updates** (kwafi + sauya) a React/Redux, kuma rest yana sa aiki variadic da "dauki saura" destructuring tsanni.