Creating Clock in React
I have a website and I want to put a realtime clock on one of the pages. I have written the code using hooks but I understand using hooks for such cases is bad for performance due to rerenders in states every second. Is there a less resource intensive solution?
import { useEffect, useState } from 'react'
export default function Footer() {
const [time, setTime] = useState()
useEffect(() => {
setInterval(() => {
const dateObject = new Date()
const hour = dateObject.getHours()
const minute = dateObject.getMinutes()
const second = dateObject.getSeconds()
const currentTime = hour + ' : ' + minute + ' : ' + second
setTime(currentTime)
}, 1000)
}, [])
return <div>{time}</div>
}
Solution 1:
It's definitely good that you're thinking about performance however in this situation I wouldn't change a single thing. In order to change what gets rendered to the screen (in this case the text of the clock), the component has to be re-rendered to reflect the change in it's state, which is not such a bad thing. Each time the component re-renders it's not going to cause the parent to re-render so performance-wise we're doing just fine.