Nested components in React JS

In this post, you will see

1. first, how one function component can be used inside another function component.
2. second, how one function component can be defined inside another function component. 

This is a common practice for creating modular and reusable UI components.

Here's an example of using one function component inside another:

IndependentOne Component:

import React from 'react'

function IndependentOne() {
  return (
    <div>
      <h3>IndependentOne</h3>
    </div>
  )
}

export default IndependentOne

IndependentTwo Component:

import React from 'react'

function IndependentTwo() {
  return (
    <div>
      <h3>IndependentTwo</h3>
    </div>
  )
}

export default IndependentTwo

Now we use IndependentOne component inside IndependentTwo component. Note that both components are independent; any of them can be used into another one.

import React from 'react'
import IndependentOne from './IndependentOne'

function IndependentTwo() {
  return (
    <div>
      <h3>IndependentTwo</h3>
      <IndependentOne/>
    </div>
  )
}

export default IndependentTwo

This demonstrates how you can compose UI components by using one component inside another in React. It's a powerful feature that allows you to create complex UIs by combining simpler, reusable components.

Next question is, can we define one component inside another component?

The answer is yes. You can define a one component inside the another component. This is often referred to as a "nested" component. Here's an example:

import React from "react";

// Parent functional component
const ParentComponent = () => {
  // Child functional component defined inside the parent component
  const ChildComponent = () => {
    return <p>This is the child component</p>;
  };

  return (
    <div>
      <h1>This is the parent component</h1>
      {/* Using the ChildComponent inside the ParentComponent */}
      <ChildComponent />
    </div>
  );
};

export default ParentComponent;

In this example:

• We define a 'ParentComponent' functional component.
• Inside the 'ParentComponent', we define a 'ChildComponent' functional component.
• We then render the 'ChildComponent' directly inside the 'ParentComponent''s JSX markup.
• When the 'ParentComponent' is rendered, it will also render the 'ChildComponent' within it.

Important:

Defining a child component inside the parent component can be useful for encapsulating functionality or UI elements that are closely related to the parent component and don't need to be reused elsewhere. However, keep in mind that the child component will only be available within the scope of the parent component and cannot be accessed or used outside of it.