JSX One Top Level Element

In JSX, you are required to have only one top-level element in the component’s JSX code. This means that when you return JSX from a component, it must have a single outermost element encapsulating all the other elements.

Here’s an example to illustrate the requirement of a single top-level element:

import React from 'react';

function MyComponent() {
  return (
    <div>
      <h1>Title</h1>
      <p>Paragraph 1</p>
      <p>Paragraph 2</p>
    </div>
  );
}

In this example, the <div> element acts as the top-level element that contains the <h1> and two <p> elements.

However, if you try to return multiple elements without a common parent, it will result in a compilation error. For instance:

import React from 'react';

function MyComponent() {
  return (
    <h1>Title</h1>
    <p>Paragraph 1</p>
    <p>Paragraph 2</p>
  );
}

The above code will generate a syntax error because there are multiple top-level elements (<h1>, <p>, and <p>) without a common parent.

To address this issue, you can use a React Fragment (<>...</>) or <React.Fragment>...</React.Fragment> to wrap the multiple elements as a single parent element:

import React from 'react';

function MyComponent() {
  return (
    <>
      <h1>Title</h1>
      <p>Paragraph 1</p>
      <p>Paragraph 2</p>
    </>
  );
}

In this updated code, the React Fragment acts as the single top-level element that encloses the <h1> and two <p> elements, allowing the code to be valid JSX.

Remember to ensure that you have only one top-level element or a single parent element when returning JSX from a component.