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Introduction to Hooks

  • This lesson introduces React Hooks and explains what Hooks are, why they were introduced, and the basic rules for using them in React applications.

  • Topic Overview

    React Hooks allow functional components to use state and lifecycle features without writing class components.
    Hooks made React simpler, cleaner, and more powerful.

    Introduction to Hooks

    Before Hooks, only class components could use state and lifecycle methods.
    Hooks were introduced to solve this limitation.

    Hooks allow functional components to manage state and side effects.

    What are Hooks?

    Hooks are special functions provided by React that let you:

    • Use state

    • Use lifecycle features

    • Manage side effects

    Hooks always start with the word use.

    Examples:

    • useState

    • useEffect

    Rules of Hooks

    React Hooks follow strict rules.

    Rules:

    1. Only call Hooks at the top level

    2. Do not call Hooks inside loops or conditions

    3. Only call Hooks inside React functions

    ❌ Wrong:

if (x) {
  useState();
}
  • Correct:

useState();

  • Following rules avoids bugs.

    Why Hooks Were Introduced

    Hooks were introduced to:

    • Reduce complex class components

    • Reuse logic easily

    • Write cleaner code

    • Avoid lifecycle confusion

    Hooks replaced most class component use cases.

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