The Basics of Building a React Apps

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Building a React apps are accessible, but you must know the basics of the language before starting. This article will teach you about the basic concepts of React and how to use components, views, and tests. You should also know what your component’s state should be, as well as how to update its state in the DOM.

Create React App

Create React App is an excellent program that allows beginners to start building single-page apps using React. The program uses a familiar environment and deploys JavaScript features, allowing you to optimize your apps and quickly become an expert react developer.

The Create React App command is effortless and requires only one dependency and minimal setup. Once you’ve set up your project with Create React App, it is a breeze to maintain and update it.

The Create React App command will set up the main structure of your app and some developer settings. Most of these settings will not be visible to visitors to your website.

However, you can use the “webpack” tool to transform the contents of your application directory into static assets that visitors will see. This will help you to build a smaller application bundle, as well as load content on demand.

This command will download and run the package create-react-app. It will also run the test, build, and eject scripts. This command gives you complete control over the output and allows for customization.

It is a good idea to include the -a flag when you run the order so the result consists of hidden files and libraries. It will also include external JavaScript libraries installed in the node_modules/ directory. It also consists of the public/ directory, which contains base HTML, JSON, and image files.

When creating a Create React App, you should first set up a local development environment. Then, you should install the webpack development server.

This server will then launch a watcher that reloads the application automatically whenever you make changes. You can also use the ‘fast refresh’ option to preserve the state of hooks and functional components. It will automatically reload the application whenever a syntax error is detected.


Components in React are a set of tags that refer to different types of elements in a web page. This allows components to abstract away different levels of detail. Among these tags is the component title. The component’s title function can be written in plain JS, but it returns a block of HTML.

The HTML block does not have to be in a string format. The HTML block is written in JSX, an extension of HTML. It has a syntax compatible with regular JavaScript and is converted into plain vanilla JS by the build system.

Building React applications requires some planning and decision-making. Many decisions will influence how the app scales, collaborates and works with different tools and needs. Fortunately, there are tools available that will make the process easier. This guide will show you how to add React components to your HTML page.

In addition to components, you can also use plain old stylesheets. These can be reused by adding them to a parent component. This works well when the number of members in the project is small. You can also reuse custom components. However, you must be careful that the custom components are a manageable size.

Components allow you to split up your UI into small pieces, enabling you to think about each piece in isolation. A member is similar to a JavaScript function in that it accepts a single “props” object as input. The component will then return the appropriate React element.


When building a React app, you should be familiar with the differences between Views and Components. Views can be used to render a component in the DOM. Members have a setState method that signals when their state changes. React will then update the element in the DOM with the new state.

Components are a great way to organize your code. A common approach is to break up your app’s UI design into multiple components. This will allow you to live-update your app as you make changes. Using React components, you’ll be able to add and remove components without worrying about recompilation.

React supports state and props, and these two types of data can be manipulated differently. For example, if you want to use a revolving door, you can use a single component with many different functional components. This way, you can swap the functionality of each of your components as needed. Flux implementations can even be used to externalize logic and state.

Ideally, your component hierarchy comprises components and a joint owner component. This common owner component should be above all the other components in the order. This allows you to reuse other components and pass data using props, a way to give data from parent to child. Remember the DRY principle when creating an app: Don’t Repeat Yourself!


One of the best ways to ensure your React app is bug-free is by writing tests. You can write several types of tests, including UI and end-to-end tests. Both methods will help ensure that the application works appropriately before releasing. The process is also known as test-driven development.

Whether you’re writing tests for individual components, or an entire application, you’ll want to ensure you use the correct tools. There are a few popular libraries for writing tests.

You can also use the react-test-renderer to test your component’s behavior. This component contains a span tag that displays the current value of the counter. This will let you quickly determine if the component is working as expected. Having a test for this component will ensure that your code is error-free.

When building a React app, you should write tests for each component. Using the available modules and frameworks, you can efficiently run these tests. The important thing is to make sure that all features are tested – especially those that require user engagement. This includes features that take input or retrieve data and even those that process sequential events.

ES6 syntax

In building React apps, it’s essential to use ES6 syntax. This version of the JavaScript language is preferred over ES5. This is because ES6 offers more significant support for native code. React is an example of a modern web app that uses a streamlined approach to creating components.

ES6 has some critical differences from ES5. Most notably, it uses a more concise syntax. The language supports variables such as numbers, string, null, Boolean, and symbols.

You can also use the var and let keywords to declare variables. ES6 also supports the import module and function keyword and can import JSX files. The ES6 syntax is more concise, making it easier to read.

ES6 syntax also supports destructuring. This feature allows you to extract only the values needed in a specific context. The example below shows how to extract the value of the color property from an object. Note that the object properties have duplicate names, which can be removed with the help of destructuring.

For a modern web application, you can use ES6 syntax using a build system like Babel. This tool provides many powerful features that you’ll find helpful in a React app, including dynamic imports and a modern JavaScript ecosystem.

JavaScript ecosystem support

Building React applications requires several tools. One such tool is a package manager, which lets you take advantage of a large ecosystem of third-party packages.

This package manager also allows you to install updates easily. The other tools include a compiler and a bundler, which help you write modular, well-optimized code. The bundler can be used to create lightweight packages to minimize load time.

Another popular tool with React is JSX, a JavaScript extension syntax similar to HTML that gives developers a way to structure component rendering. Most React components are written in JSX, although you can also use pure JavaScript code. It has built-in hooks, such as useState, to control state and useEffect for side effects.

Using a package manager helps developers avoid wasting hours on manual search and installation of dependencies.

This is important because it allows developers to create better applications with optimized code. Using a package manager will also update libraries when necessary. This makes it easy for developers to work efficiently and create better applications.

Building React apps with JavaScript ecosystem support is possible with the help of Webpack, a module bundler that makes it easy to create and use. Another helpful tool is the Babel compiler, which supports ECMAScript 6 and 7. This enables developers to use JavaScript code within their React applications.