Lesson 7: Lists, Keys and Conditional Rendering in React (and the '0' Bug)

Almost every screen shows a list. Learn to render lists with map, understand why keys matter, add search, filters and sorting, and show the right UI for every condition. In this lesson (Lesson 7 of 20 in the "React JS: Beginner to Advanced" course) you will learn: Rendering lists with map Why keys matter, with a live demo of the index-key bug Search, filter and sort as derived data Four ways to render conditionally The famous '{0 && ...}' bug Designing empty states YOUR TASK: Build a movie list with search, a genre dropdown, sort by year and a 'No movies found' message. ------------------------------------------ ABOUT THIS COURSE "React JS: From Beginner to Advanced" is a free, step-by-step video course that takes you from your first component to full-stack, production-ready apps. 20 lessons and 5 real-world projects with React 19, Vite, React Router, TanStack Query, Zustand, Redux Toolkit, React Hook Form, Zod, Tailwind CSS, TypeScript, Vitest, and an ASP.NET Core Web API (.NET 10) back end with JWT and SignalR. Full course playlist:    • React JS Full Course: Beginner to Advanced...   previous Lession 6    • Lesson 6: React useState and Events: Re-re...   Lession 5    • Lesson 5: React Props Explained: Passing D...   Lession 4    • Lesson 4: JSX and Components in React: Rul...   Lession 3    • Lesson 3: React Setup with Vite: Node.js, ...   Lession 2    • Lesson 2: Modern JavaScript for React: Arr...   Lession 1    • Lesson 1: What is React? Components, SPAs ...   AI in asp.net core Full Course Video link English and Hindi English version:    • AI with ASP.NET Core: Full Course for C# D...   Hindi playlist:    • AI with ASP.NET Core Hindi में | C# Develo...   Subscribe for the next lesson, and tell me in the comments what you are building with React! #React #ReactJS #JavaScript #Frontend #WebDevelopment #CodingTips