React Tutorial

React Tutorial

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1. Getting Started

The prompt provides a list of terms that are commonly used in React, a popular JavaScript library for building user interfaces. The terms include React, component, virtual DOM, JSX, constructor() method, render() method, state, setState() method, props, and binding methods. The prompt does not provide any additional context or information about these terms.

What is a Component?

State and setState()

Props (properties)

Binding Methods

2. Lifecycle Methods

Now that we have become familiar with most of the React basics and how components work and integrate into the development of a website. Since we know that React components are loaded onto the main page and then can be dynamically updated which means that they go through a certain cycle of stages that can be intervened in and the behavior can be updated. This cycle can be manipulated through what are called lifecycle functions at different stages. React class component lifecycle methods are used for a variety of purposes, including performing setup tasks when a component is first rendered, updating a component in response to changes in props or state, and cleaning up any resources that the component is using.

componentWillMount()

componentWillUnmount()

componentDidMount()

shouldComponentUpdate()

componentDidUpdate()

componentDidCatch()

Overview of Component Lifecycle

3. Functional Components and Hooks

Now that we have gone over the basics of class-based components, we will now explore a better and more concise way to write React components with functional components which are a lot more commonly used in React these days. Functional components are a way to define components in React that are simple, lightweight, and only consist of a render function. They are a great choice for simple, presentational components that only need to render some JSX and don't have their own state or lifecycle methods. In this section of the course, we'll look at how to use functional components with Hooks to manage state and other lifecycle events.

What is a Hook?

useState()

4. Advanced Topics

Now, we understand the basics of React with regards to the various kinds of components available and how to use them and exploit their lifecycle to our advantage in a webpage, we will now move on to some advanced topics. These topics will deal with topics like state management through Context API and the Consumer and Provider architecture in React and how these things make life easier in a production-level React App. Then we will move onto Routing in react and how it all works to produce a navigable React App without having to reload the page. This involves studying an important React package called “react-router-dom” which we will get into in this section.

React Router Dom

Course Content

React Tutorial

React Tutorial

useState()

useState is a Hook in React that allows you to add state to functional components. It is a way to manage and update the state of a component without converting it to a class component.

To use useState, you first need to import it from the react package. Then, you can call the useState function inside your component and pass it an initial state value. It will return an array with two values: the current state value and a function that can be used to update the state value.

Here is an example of how to use useState:

In this example, the useState Hook is called inside the MyComponent functional component. It takes an initial state value of 0 as an argument and returns an array with two values: count, which is the current state value, and setCount, which is a function that can be used to update the state value.

The component then increments the count by calling setCount with the new value, and renders the count.

There are a few nuances to be aware of when using useState. First, the state value is updated asynchronously, so if you need to update the state value based on the current state value, you should pass a function to setCount rather than an immediate value. For example:

Second, the state value is only updated when the component re-renders, so if you need to update the state value based on an external event or a prop change, you may need to use an effect to trigger a re-render. For example:

In this example, the useEffect Hook is used to update the state value when the initialCount prop changes.

useState is a powerful and flexible Hook that allows you to add state to functional components. It is a key part of modern React development and can help you write cleaner, more readable code.

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Section 3. Chapter 3

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