How can we do batch update of useState

[numandev1]

reference: reactwg/react-18#21

What is batching?

Batching is when React groups multiple state updates into a single re-render for better performance.

how can we achieve batch updates in React Native?

[AwaisIbrar8]

I think the framework handles batches itself.
React uses a concept called "reconciliation" to optimize updates to the UI. When you update the state of a component, React will batch multiple updates together and perform them at once, rather than updating the UI immediately after each change.

[numandev1]

but in react native batching is not occuring

[AwaisIbrar8]

I didn't check it. But I am thinking that it's happening. May be wrong mentioned in the documentation

[numandev1]

i checked it, batching is working on react web but not working in react native side. may be we have to use fabric renderer👀

[Grohden]

Seems react native doesn't have support for it yet, I still see unstable_batchedUpdates available in 0.73.4, even though we're at react 18.2.0

Its pretty simple to test if batching is working:

import React, { useEffect, useState } from 'react';
import { Text, View, unstable_batchedUpdates } from 'react-native';

export const Test = () => {
  const [counterOne, setCounterOne] = useState(0);
  const [counterTwo, setCounterTwo] = useState(0);

  useEffect(() => {
    const interval = setInterval(() => {
      console.log('---------------');
      // To batch just:
      // unstable_batchedUpdates(() => {
      setCounterOne((x) => x + 1);
      setCounterTwo((x) => x + 1);
      // });
    }, 1000);

    return () => {
      clearInterval(interval);
    };
  }, []);

  useEffect(() => {
    console.log('Counter: ', counterOne, counterTwo);
  }, [counterOne, counterTwo]);

  return (
    <View
      style={{
        flex: 1,
        justifyContent: 'center',
        alignItems: 'center',
      }}>
      <Text>Counter One: {counterOne}</Text>
      <Text>Counter Two: {counterTwo}</Text>
    </View>
  );
};

Also, I'm not sure if having hermes affects that.. but we're with hermes disabled

[vksgautam1986]

New Arch supports it