# JavaScript Spread and Rest

## Spread Operator (...)

### Copying Arrays

```javascript
const arr1 = [1, 2, 3];
const arr2 = [...arr1]; // Copy
```

### Combining Arrays

```javascript
const arr1 = [1, 2];
const arr2 = [3, 4];
const combined = [...arr1, ...arr2]; // [1, 2, 3, 4]
```

### Object Spread

```javascript
const user = { name: 'John', age: 25 };
const updated = { ...user, age: 26 };
```

## Rest Operator

```javascript
function sum(...numbers) {
  return numbers.reduce((a, b) => a + b, 0);
}

sum(1, 2, 3, 4); // 10
```

## Key Takeaway

Spread expands arrays/objects. Rest collects arguments. Both use ... syntax. Essential for modern JavaScript.

Master spread and rest operators. Learn to copy arrays/objects, combine data, and handle function arguments.

JavaScript Spread and Rest Operators

Deep dive into JavaScript, JS, and ECMAScript fundamentals, ES6+, and advanced concepts.

JavaScript Spread and Rest Operators

JavaScript Spread and Rest

Spread Operator (...)

Rest Operator

Key Takeaway

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