Lesson 7 Advanced Web Programming

Why Learn React Hook

• React Hooks have become the standard approach in

modern React development.

• Most companies and React projects now prefer functional components with Hooks because they produce cleaner, more maintainable, and

reusable code

Why were React Hook Introduced

developers needed Class Components to use state and lifecycle methods. As applications became larger, class components became difficult to read, maintain, and reuse.

React introduced Hooks to:

• Reduce the complexity of class components.

• Make functional components more powerful.

• Reuse stateful logic between components.

• Improve code readability and maintainability.

• Encourage cleaner and more organized code.

Benefits of React Hooks

1. Simpler Code

2. Reusable Logic

3. Beter Readabilty

4. Easier Maintenance

5. Improved Performance

Simpler Code

Hooks eliminate the need for class components, making React

code shorter and easier to understand

Reusable Logic

Developers can extract common logic into Custom Hooks, reducing duplicate code.

Better Readability

Logic related to the same feature can be grouped together instead of being scattered across lifecycle methods

Easier Maintenance

Smaller and cleaner components are easier to debug, update, and maintain.

Improved Performance

Hooks such as useMemo and useCallback help optimize rendering performance

Before React Hooks

• Uses class components

• use this.state

• uses lifecysle methods

• more boilerplate code

• harder to understand

After React Hooks

• Uses functional components

• uses hooks like useState()

• uses useEffect()

• cleaner syntax

• easier to maintain

Common React Hooks

• useState

• useEffect

• useContext

• useRef

• useMemo

• useCallback

• useReducer

• Custom Hook

UseContext

Shares data across multiple components without passing props manually.

useRef

Accesses DOM elements or stores values that don't trigger re-rendering.

useMemo

Stores the result of an expensive calculation.

useCallback

Prevents a function from being recreated unnecessarily.

useReducer

Manages complex state logic.

Custom Hook

Creates reusable logic that can be shared between component

How React Hook Works

• Hooks are called inside a functional component. When React renders the component,

• it executes each Hook in the same order every time, allowing React to preserve state and other Hook values between renders.

Rules of React Hooks

• Only call Hooks at the top level of a component.

• Do not call Hooks inside loops, conditions, or nested functions.

• Only call Hooks inside React functional components or Custom Hooks.

• Always import the required Hook before using it.

Real world uses of React Hooks

• Build interactive forms

• Create counters

• Fetch data from APIs

• Display real-time notifications

• Handle authentication

• Switch themes (Dark Mode / Light Mode)

• Manage shopping carts

• Build dashboards

• Create chat applications