JavaScript Array Methods: Complete Guide

Why Array Methods?

Array methods make working with arrays easy. No need for loops!

``` Without Methods: ┌─────────────┐ │ for loop │ │ if checks │ │ manual │ └─────────────┘

With Methods: ┌─────────────┐ │ .map() │ │ .filter() │ │ .reduce() │ └─────────────┘ ```

map(): Transform Every Element

```javascript const numbers = [1, 2, 3]; const doubled = numbers.map(n => n * 2); // [2, 4, 6] ```

filter(): Keep Matching Elements

```javascript const numbers = [1, 2, 3, 4, 5]; const evens = numbers.filter(n => n % 2 === 0); // [2, 4] ```

reduce(): Combine to Single Value

```javascript const numbers = [1, 2, 3, 4]; const sum = numbers.reduce((acc, n) => acc + n, 0); // 10 ```

find(): Find First Match

```javascript const users = [{id: 1, name: 'John'}, {id: 2, name: 'Jane'}]; const user = users.find(u => u.id === 2); // {id: 2, name: 'Jane'} ```

some() and every()

```javascript const ages = [18, 20, 25]; ages.some(age => age < 18); // false ages.every(age => age >= 18); // true ```

Key Takeaway

Array methods simplify array operations. map transforms, filter selects, reduce combines. Use these instead of loops for cleaner code.