Mastering React Series: React Components

React Components are the building blocks of any React application. They are independent, reusable, and composable units that define a piece of the UI. In React, everything is a component, including the UI, forms, modals, etc.


Types of React Components

There are two main types of React Components:

  1. Class Components
  2. Function Components

Class Components

Class components are JavaScript classes that extend React.Component class. They use a class-based syntax to define a component, and they are used when you need to handle state or lifecycle methods.

Example: 


Lifecycle Methods in Class Components

Class Components have lifecycle methods that allow you to perform actions at specific points during the component's lifecycle. These methods are called automatically by React, and they give you control over the component's behavior and state.

Examples of lifecycle methods include:

  • componentDidMount: called after the component has mounted (added to the DOM)
  • componentDidUpdate: called after the component has updated (re-rendered)
  • componentWillUnmount: called just before the component is unmounted (removed from the DOM)

Here's an example of a Class Component using the componentDidMount lifecycle method:


Function Components

Function components are just JavaScript functions that return a React element. They are simple, fast, and easy to understand, and they are used when a component only needs to render based on its props.
Example:


Hooks in Function Components

React Hooks are a way to add state and other advanced features to Function Components. They were introduced in React 16.8, and they allow you to add state and lifecycle methods to Function Components, making them more powerful and versatile. Examples of React Hooks include:
  • useState: used to add state to a Function Component
  • useEffect: used to perform side effects in a Function Component
  • useContext: used to access the context in a Function Component
Here's an example of a Function Component using the useState and useEffect Hooks:


Where to use Class and Function Components

Class Components are best suited for components that need to manage state, handle lifecycle methods, or have a complex UI logic. Function Components are best suited for components that only need to render based on their props, and have a simple UI. With the addition of React Hooks, Function Components can now handle state and other advanced features, making them a more versatile option. In general, it's recommended to use Function Components with Hooks whenever possible and only switch to Class Components when necessary. This is because Function Components with Hooks are easier to understand, maintain, and test, and they also perform better in most cases. Conclusion:
React Components are the fundamental building blocks of any React application. They allow you to break down complex UI into smaller, reusable, and composable units. Class Components and Function Components are the two main types of React Components, and they can be used based on the specific needs of your application. With the addition of React Hooks, Function Components have become even more versatile and powerful, making them a more popular choice for most components in a React application.


Note: I believe in the power of hands-on learning, which is why I've chosen to provide images instead of code snippets in this tutorial. By writing down the code yourself, you'll not only learn the syntax but also gain a deeper understanding of React Components and strengthen your overall grasp of the subject.

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