How to disappear alert after 5 seconds in React JS?

Question

import { useState } from 'react'
    
    const Message = ({ variant, children }) => {
      const [timeOut, setTimeOut] = useState(null)
    
      setTimeout(() => {
        setTimeOut(1)
      }, 3000)
    
      return (
        timeOut !== 1 && <div className={`alert alert-${variant}`}>{children}</div>
      )
    }
    
    Message.defaultPros = {
      variant: 'info',
    }
    
    export default Message

I want to disappear this alert after 2 or 3 seconds. I used this logic it's fine and working but In my console, I'm having this warning:

Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.

Is it affecting my app or is it oka? You can give me a better idea to implement this logic.

Answer 1

You can read through the comments

import { useState, useEffect } from 'react'
    
const Message = ({ variant, children }) => {
  const [show, setShow] = useState(true)

  // On componentDidMount set the timer
  useEffect(() => {
    const timeId = setTimeout(() => {
      // After 3 seconds set the show value to false
      setShow(false)
    }, 3000)

    return () => {
      clearTimeout(timeId)
    }
  }, []);

  // If show is false the component will return null and stop here
  if (!show) {
    return null;
  }

  // If show is true this will be returned
  return (
    <div className={`alert alert-${variant}`}>
      {children}
    </div>
  )
}

Message.defaultPros = {
  variant: 'info',
}

export default Message;