Let’s make a calculator app using ReactJS

Intro to ReactJS

ReactJS offers grateful solutions to some of front-end programming’s issues. ReactJS allowing you to build dynamic and interactive web apps easily. ReactJS (also known as React.js or React) is an open-source front-end JavaScript library for building user interfaces or UI components. Single-page web applications or mobile applications can be developed by using ReactJS. However, ReactJS is only support for the state management and rendering that state to the DOM. Therefore, additional libraries for routing is usually requires for creating React applications.

This article helps you to develop a calculator app with ReactJS. First you have to set up your environment with Node.js and ReactJS. Then you have to create the react app. You can use following steps to successfully create the react app.

Screenshot by Author

Screenshot by Author

Note

npx on the second image is not a typo — it’s a package runner tool that comes with npm.

Create React App is a comfortable environment for learning React for a beginner. Also, this is the best way to start building a new single-page application in React. You can use the latest JavaScript features by setting up your development environment. Create React App doesn’t handle backend logic or databases; it only creates a frontend, so if you want you can use it with any backend.

After successfully create the react app, you can see the folder structure as follows,

Screenshot by Author

ReactJS components

Then you have to create the components of your application. Before go into component implementation, let’s look at what is this ‘component’ in ReactJS. Components are independent and reusable bits of code. They serve the same purpose as JavaScript functions, but work in isolation and return HTML via a render() function. In this application, three components are created. First you need to import react using ‘import’ function and then you have to import your components. Following figures show how this ‘import’ feature can be used in our application and show three components in our application.

output.js

outputRow.js

layout.js

An element describing a component is also an element.

Now you have some kind of idea about react components and how they interconnect within an application. Let’s dive into our ‘css classes’ in RectJS. If you prefer to add some css properties you can add them as .css files. You can add styles like hover, color etc. to your buttons. Also, font styles can be added to make your application more attractive to the end users. In this application ‘digital-7 font style was used.

outputRow.css

After following above steps you will be having a calculator app like bellow.

Here is the link to the GitHub repository.

Thank you for reading 🤗 !!! Hit a clap if this article is helpful for you.