Batching ⚙️

In ReactJS, batching refers to a process that helps improve the performance of rendering updates to the user interface. It involves grouping multiple state updates or other React operations into a single batch, which is then processed together by React, reducing the number of actual updates performed.

Batching is particularly useful when you have multiple state updates happening one after another, as it allows React to optimize and minimize the number of times it needs to update the UI. Instead of triggering a re-render for each individual update, React will wait until the end of the batch and then perform a single re-render.

Here's a simple example to demonstrate batching in ReactJS:

import React, { useState } from 'react';

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

  const increment = () => {
    setCount(count + 1);
    setCount(count + 1);
    setCount(count + 1);
  };

  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={increment}>Increment</button>
    </div>
  );
}

export default Counter;

In the above code, we have a Counter component that maintains a count state using the useState hook. Inside the increment function, we update the count state three times in a row.

Since React batches state updates that occur within the same event handler, instead of performing three separate renders for each setCount call, React will combine them into a single update. As a result, the UI will only re-render once with the final value of count.

This batching optimization can help prevent unnecessary re-renders and improve the performance of your React application when you have multiple state updates happening closely together.