React interview question

What is JSX?


JSX ( JavaScript Expression ) allows us to write HTML elements in JavaScript and place them in the DOM without any createElement() or appendChild() methods. JSX converts HTML tags into react elements. React uses JSX for templating instead of regular JavaScript. It is not necessary to use it, however, following are some pros that come with it.

  • It is faster because it performs optimization while compiling code to JavaScript.
  • It is also type-safe and most of the errors can be caught during compilation.
  • It makes it easier and faster to write templates.

When JSX compiled, they actually become regular JavaScript objects. For instance, the code below:

const hello = <h1 className = "greet"> Hello World </h1>

will be compiled to

const hello = React.createElement {
    type: "h1",
    props: {
      className: "greet",  
      children: "Hello World"


export default function App() {
  return (
    <div className="App">
      <h1>Hello World!</h1>

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