The Relationship Between React and JavaScript

JavaScript has long been the backbone of web development, enabling dynamic and interactive user experiences. In recent years, React has emerged as a powerful JavaScript library for building user interfaces, offering developers a component-based approach to building UIs. In this blog, we’ll delve into the relationship between React and JavaScript, exploring how they complement each other and how they differ.

Understanding JavaScript:

JavaScript is a versatile programming language that runs in the browser, enabling developers to create interactive web pages and web applications. It’s a high-level, interpreted language with dynamic typing and supports both object-oriented and functional programming paradigms.

Here’s a simple example of JavaScript code to create a basic function:

function greet(name) {
  return 'Hello, ' + name + '!';

console.log(greet('John')); // Output: Hello, John!

JavaScript allows for manipulation of the Document Object Model (DOM), handling events, and asynchronous operations through features like callbacks, promises, and async/await.

Introducing React:

React, developed by Facebook, is a JavaScript library for building user interfaces. It utilizes a component-based architecture, where UIs are broken down into reusable components. React provides a declarative syntax for describing how the UI should look, and it efficiently updates and renders components based on changes to their state.

Let’s look at a basic React component:

import React from 'react';

class Greeting extends React.Component {
  render() {
    return <h1>Hello, {}!</h1>;

export default Greeting;

In this example, we’ve created a ‘Greeting' component that takes a ‘name‘ prop and displays a greeting message.

Relationship Between React and JavaScript:

React is built with JavaScript and relies heavily on its features and syntax. React components are essentially JavaScript classes or functions that return React elements (JSX), which ultimately compile down to JavaScript functions.

React leverages JavaScript’s ability to handle functions as first-class citizens, allowing developers to pass functions as props to components, manage component state using JavaScript objects, and perform various operations using JavaScript’s built-in methods and functions.

Here’s an example of a React component using JavaScript functions and state:

import React, { useState } from 'react';

function Counter() {
  const [count, setCount] = useState(0);

  return (
      <p>Count: {count}</p>
      <button onClick={() => setCount(count + 1)}>Increment</button>

export default Counter;

In this component, we use the ‘useState‘ hook from React to manage the component’s state. The 'setCount' function updates the ‘count' state, and JavaScript’s arrow function syntax is used to define the click event handler.


JavaScript and React are closely intertwined, with React building upon the core features and syntax of JavaScript to create powerful and dynamic user interfaces. By understanding JavaScript fundamentals and how they are applied within React components, developers can leverage the full potential of both technologies to build scalable and interactive web applications. Whether you’re a beginner or an experienced developer, mastering JavaScript alongside React is essential for building modern web applications.