P3.5: JS Advanced Iterators

Iterators are methods used to transform and analyze array lists without writing verbose loops.

1. Map, Filter, and Reduce

• map(): Transforms each item in an array, returning a new array.
• filter(): Returns items that match a condition.
• reduce(): Compiles the array into a single accumulated result.

const numbers = [1, 2, 3, 4];
const doubled = numbers.map(n => n * 2); // [2, 4, 6, 8]
const evens = numbers.filter(n => n % 2 === 0); // [2, 4]

Kent C. DoddsView Profile 🔗

Real-World Developer Case Study

9 Years Exp

RoleJavaScript Educator

Salary₹60 Lakhs/yr equivalent

CompanyRemix / Epic Web

Core Tech Stack

React componentsJS functional arrays

“React relies completely on map and filter for rendering HTML lists. You must master these iterations to write clean React apps.”