Cryptocurrency has become a buzzword in recent years, with many people investing in it as an alternative form of investment. Cryptocurrency operates on decentralized, secure and transparent systems and uses encryption techniques to regulate the creation of new units and verify transactions. With the rise of cryptocurrency, there has been an increased demand for tools to help people keep track of their investments in real-time.

In this article, we will explore how to build a cryptocurrency tracking application using ReactJS and CoinMarketCap API. ReactJS is a popular JavaScript library for building user interfaces, and CoinMarketCap API is a widely used API for retrieving cryptocurrency market data.

The objective of this article is to provide a comprehensive guide for developers and non-developers alike on how to build a cryptocurrency tracking application. We will start by explaining the basics of ReactJS, integrating the CoinMarketCap API, building the user interface, and finally deploying the application.

By the end of this article, you will have a basic understanding of ReactJS and how to use the CoinMarketCap API to retrieve and display cryptocurrency market data in real-time. You will also have hands-on experience in building a cryptocurrency tracking application from scratch, making it easier for you to develop more complex applications in the future.

Understanding ReactJS

A. What is ReactJS

ReactJS is a popular JavaScript library for building user interfaces. It was developed and maintained by Facebook and has been widely adopted by many companies and developers for building web applications. ReactJS works by creating components, which are small, reusable blocks of code that represent a specific part of the user interface. These components can be combined to form a complete application.

ReactJS uses a virtual DOM (Document Object Model) to update the user interface efficiently. The virtual DOM is a lightweight in-memory representation of the actual DOM, which is updated when the state of the application changes. ReactJS only updates the parts of the DOM that have changed, making it more efficient than other JavaScript libraries that update the entire DOM on each change.

B. Advantages of using ReactJS for building applications

There are several advantages to using ReactJS for building web applications:

1. Reusability: ReactJS components can be easily reused, making it easier to maintain and scale the application.

2. Performance: ReactJS uses a virtual DOM to update the user interface efficiently, making it faster than other JavaScript libraries.

3. Easy to learn: ReactJS has a simple syntax and is easy to learn, even for developers who are new to JavaScript.

4. Large community: ReactJS has a large and active community of developers who contribute to the library and provide support to other developers.

5. Integration with other libraries: ReactJS can be easily integrated with other libraries, making it easy to add new functionality to the application.

C. Setting up a ReactJS project

To get started with ReactJS, you will need to set up a development environment. Here are the steps to set up a ReactJS project:

1. Install Node.js: Node.js is a JavaScript runtime that allows you to run JavaScript on the server-side. It is required for ReactJS development.

2. Install a code editor: A code editor is a software application that provides a text editor for writing code. Some popular code editors include Visual Studio Code, Sublime Text, and Atom.

3. Create a new project: To create a new ReactJS project, you can use the Create React App command-line tool. To install Create React App, run the following command in your terminal:

npx create-react-app my-app

This will create a new ReactJS project in a directory called "my-app".

4. Start the development server: To start the development server, navigate to the project directory and run the following command:

npm start

This will start a local development server and open the application in your browser.

With these steps, you have successfully set up a ReactJS project and are ready to start building your application. In the next section, we will integrate the CoinMarketCap API into the ReactJS project.

Integrating CoinMarketCap API

A. Introduction to CoinMarketCap API

CoinMarketCap API is a widely used API for retrieving cryptocurrency market data. It provides real-time data on various cryptocurrency markets, including price, volume, and market capitalization. The API is easy to use and provides a wide range of data that can be used for various purposes, including building cryptocurrency tracking applications.

B. Getting an API Key from CoinMarketCap

To use the CoinMarketCap API, you will need to get an API key. An API key is a code that is passed in by the client to access the API. The API key is used to track the usage of the API and to prevent unauthorized access.

Here are the steps to get an API key from CoinMarketCap:

1. Create an account: To get an API key from CoinMarketCap, you will need to create an account on their website.

2. Get an API key: After creating an account, you can get an API key by visiting the API section of the CoinMarketCap website. To access the API section, click on "API" in the top menu.

3. Choose a plan: CoinMarketCap offers different plans for the API, including a free plan and paid plans with more data and higher rate limits. Choose the plan that best fits your needs.

4. Get the API key: After choosing a plan, you can get your API key by clicking on "Get API Key". The API key will be displayed on the screen, and you can use it to access the API.

C. Fetching data from the API and storing it in React state

Once you have an API key, you can use it to retrieve data from the CoinMarketCap API. ReactJS has a built-in method for fetching data from APIs, called "fetch". The fetch method retrieves data from an API and returns a Promise, which can be used to access the data.

To fetch data from the CoinMarketCap API, you will need to make a GET request to the API endpoint. The endpoint for retrieving cryptocurrency data is:

https://pro-api.coinmarketcap.com/v1/cryptocurrency/listings/latest

The fetch method can be used to make a GET request to the API endpoint and retrieve the data. Here is an example of how to fetch data from the CoinMarketCap API in ReactJS:

const [data, setData] = useState([]);

useEffect(() => {

  const fetchData = async () => {

    const result = await fetch(

      "https://pro-api.coinmarketcap.com/v1/cryptocurrency/listings/latest",

      {

        headers: {

          "X-CMC_Pro_API_Key": "YOUR_API_KEY",

        },

      }

    );

    const json = await result.json();

    setData(json.data);

  };

  fetchData();

}, []);

In this example, the fetch method is used to make a GET request to the CoinMarketCap API endpoint and retrieve the data. The data is then stored in the "data" state using the "setData" function. The "useEffect" hook is used to fetch the data when the component is first rendered.

By storing the data in the state, you can access it from anywhere in the component and use it to build the user interface. 

Building the User Interface

A. Designing the Layout Using React Components

In this section, we will use React components to build the user interface for our cryptocurrency tracking application. React components are reusable UI elements that can be used to build the user interface.

To start, let's design the layout of the application. We will use the following components:

1. Header: A header component to display the title of the application

2. Table: A table component to display the data fetched from the API

3. Table Header: A component to display the header of the table

4. Table Row: A component to display a row of data in the table

5. Filter: A component to allow the user to filter the data by currency name

6. Sort: A component to allow the user to sort the data by various fields, such as price, volume, and market capitalization.

B. Displaying Data Fetched from the API

Now that we have designed the layout of the application, we can use the data fetched from the API to display the information in the table.

In the previous section, we stored the data fetched from the API in the state. We can now access this data and use it to populate the table.

Here is an example of how to display the data in the table:

const Table = ({ data }) => {

  return (

    <table>

      <TableHeader />

      <tbody>

        {data.map((coin) => (

          <TableRow key={coin.id} coin={coin} />

        ))}

      </tbody>

    </table>

  );

};

In this example, the "Table" component takes the "data" prop and uses it to populate the table. The "map" function is used to iterate over the data and create a "TableRow" component for each item.

C. Adding Functionality to the Application

In this final section, we will add functionality to the application to make it more user-friendly. We will add the following functionality:

1. Filter: We will add a filter component to allow the user to filter the data by currency name.

2. Sort: We will add a sort component to allow the user to sort the data by various fields, such as price, volume, and market capitalization.

Here is an example of how to add filtering functionality to the application:

const Filter = ({ handleFilterChange }) => {

  return (

    <form>

      <input

        type="text"

        placeholder="Filter by currency name"

        onChange={(event) => handleFilterChange(event.target.value)}

      />

    </form>

  );

};

const App = () => {

  const [data, setData] = useState([]);

  const [filteredData, setFilteredData] = useState([]);

  useEffect(() => {

    // fetch data from API and store in state

  }, []);

  const handleFilterChange = (value) => {

    setFilteredData(

      data.filter((coin) => coin.name.toLowerCase().includes(value.toLowerCase()))

    );

  };

  return (

    <div>

      <Header />

      <Filter handleFilterChange={handleFilterChange} />

      <Table data={filteredData.length > 0 ? filteredData :

Deploying the Application

A. Overview of Deployment Options

Once the development of the cryptocurrency tracking application is complete, it's time to deploy it so that it can be used by others. There are several options for deploying a ReactJS application, including:

1. GitHub Pages: A free and easy-to-use platform for hosting static web pages, including ReactJS applications.

2. Firebase: A platform that provides a hosting service for web and mobile applications.

3. AWS: Amazon Web Services provides a range of services for hosting web applications, including EC2 and S3.

4. Heroku: A cloud platform that enables developers to build, run, and operate applications entirely in the cloud.

B. Deploying the ReactJS Application on GitHub Pages

GitHub Pages is a free and easy-to-use platform for hosting static web pages, including ReactJS applications. In this section, we will go through the steps to deploy our cryptocurrency tracking application on GitHub Pages.

1. Create a GitHub repository: Go to the GitHub website and create a new repository for your application.

2. Push your code to the repository: Use Git to push your code to the repository you just created.

3. Install the gh-pages package: In your terminal, run the following command: npm install --save-dev gh-pages

4. Add a homepage field to your package.json file: Add the following line to your package.json file:

"homepage": "https://{your-github-username}.github.io/{your-repository-name}",

5. Add a predeploy and deploy script to your package.json file: Add the following lines to your package.json file:

"scripts": {

  "predeploy": "npm run build",