Array Methods

Modern arrays come with powerful methods that let you transform data without writing manual loops.

• map builds a new array by transforming each item
• filter keeps only items that pass a test
• reduce combines all items into one value
• forEach runs a function for each item

const nums = [1, 2, 3, 4];
const doubled = nums.map(n => n * 2);
const evens = nums.filter(n => n % 2 === 0);
const total = nums.reduce((sum, n) => sum + n, 0);