How do I make a controlled React login form input editable with useState?

Provide an onChange handler that updates state, such as onChange={e => setEmail(e.target.value)}.

How can useEffect replace componentDidMount, componentDidUpdate, and componentWillUnmount?

Use useEffect for mount and updates; return a cleanup function from it to run on unmount.

How do I stop a React form from reloading the page when it is submitted?

Call event.preventDefault() inside the handleSubmit function.

Free online course React Hooks Tutorial

Duration of the online course: 1 hours and 17 minutes

New

Build modern React apps faster with Hooks. Learn state, effects, context and custom patterns in this free course—ideal for job-ready web development skills.

In this free course, learn about

What React Hooks are and why/when to use them instead of class lifecycle methods
Managing component state with useState(), including initial state and updates
Building controlled forms with useState(): binding value and handling onChange
Fixing read-only inputs: add onChange handlers when input value is driven by state
Using useEffect() like componentDidMount with an empty dependency array
Using useEffect() like componentDidUpdate by specifying dependency arrays
Cleanup in useEffect() to mimic componentWillUnmount and avoid leaks/subscriptions
Sharing state via useContext(): creating, providing, and consuming context values
State management with useReducer(): actions, reducers, dispatch, and initial state
Advanced useReducer patterns (part 2): multiple actions and cleaner state logic
Using useRef() for persisting mutable values and accessing DOM elements
Creating Custom Hooks to reuse stateful logic across components
Preventing form submit page reload: call event.preventDefault() in handleSubmit

About the free online course

React Hooks changed how developers build interfaces by making components simpler, cleaner, and easier to scale. In this free online course, you will learn how to replace common class-based patterns with a practical, modern Hooks workflow that fits real product development. If you want to write React code that feels current, maintainable, and production-friendly, this course helps you get there step by step with focused explanations and hands-on practice.

You will start with the why behind Hooks, then quickly move into using state in functional components with useState, including the kind of form handling you need for everyday UI work such as login screens. You will learn how controlled inputs work, how to keep the UI responsive, and how to prevent common issues that break typing or cause confusing behavior when values come from component state. Along the way, you will gain a clear mental model for how updates happen and how to design predictable state flows.

Next, you will master useEffect by mapping it to familiar lifecycle behaviors: running logic when a component first mounts, responding to updates, and cleaning up side effects when a component unmounts. This makes it easier to handle tasks like fetching data, subscribing to events, and preventing memory leaks. You will also explore shared state with useContext, then move to more structured state management with useReducer for complex interactions and predictable updates.

To round out your toolkit, the course covers useRef for persisting values and working with DOM references without triggering rerenders, and it ties everything together with custom Hooks so you can reuse logic across components. By the end, you will be able to build React interfaces with less boilerplate, clearer separation of concerns, and a stronger foundation for real-world web development projects.

Course content

Video class: React Hooks Tutorial #1 - Introduction to hooks || Codenemy 04m
Video class: React Hooks Tutorial #2 - useSate() hook || Codenemy 04m
Video class: React Hooks Tutorial #3 - useState() with form || Codenemy 08m
Exercise: In a React login form using the useState Hook, what must be added to inputs so users can type after setting the input's value from state?

Video class: React Hooks Tutorial #4 - useEffect Hook as ComponentDidMount || Codenemy 06m
Video class: React Hooks Tutorial #5 - useEffect Hook as ComponentDidUpdate() || Codenemy 04m
Video class: React Hooks Tutorial #6 - useEffect Hook as ComponentWillUnmount() || Codenemy 10m

Video class: React Hooks Tutorial #7 - useContext Hook || Codenemy 05m
Video class: React Hooks Tutorial #8 - Introducing useReducer() Hook part 1 || Codenemy 05m
Video class: React Hooks Tutorial #9 - Introducing useReducer() Hook part 2 || Codenemy 12m

Video class: React Hooks Tutorial #10 - useRef Hook || Codenemy 04m
Video class: React Hooks Tutorial #11 - Custom Hooks || Codenemy 10m
Exercise: React में form submit करते समय page reload रोकने के लिए handleSubmit में क्या किया जाता है?

Learn aboutReact JS

Explore the best free online React JS courses and learn to build fast, interactive web applications with hands-on lessons for beginners and aspiring developers. Study React components, hooks, state, props, routing, and modern front-end development at your own pace. Enroll today for free training and earn a certificate to showcase your React JS skills.

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Explore the best free online JavaScript courses with certificates and build in-demand web development skills at your own pace. Learn JavaScript fundamentals, DOM manipulation, ES6, APIs, frameworks, and more through beginner-friendly and advanced classes. Enroll today, earn a certificate, and strengthen your resume for developer career opportunities.