I've been learning React and I read that the function returned from useEffect is meant to do cleanup and React performs the cleanup when the component unmounts.  So I experimented with it a bit but found in the following example that the function...

Inside of my useEffect, I have a props dependency (setIsValid). When I add this dependency to the useEffect, it lands in an infinite loop.  Parent when Calling Child Component:  const setIsValid = (bool) => {   const tmpStateCopy = Object.assign({...

On this answer by Dan Abramov here on SO, I've found out the following:  Does React keep the order for state updates?     Currently (React 16 and earlier), only updates inside React event handlers are batched by default. There is an unstable API...

So I have the following situation when using a useEffect that calls a functions that depends on state.  Example:  // INSIDE APP COMPONENT  const [someState, setSomeState] = React.useState(0); const [someTrigger, setSomeTrigger] = React.useState(false...

I can't seem to to get reed of this error for some reason; I've looked into it, callbacks, including the code in the useEffect, but it isn't working for me (or I'm doing it wrong).  Here is the code:   import React, { useEffect, useSt...

I am trying to use the useEffect to grab some data from an API. I am succesful in grabbing the data but after I set my state and try to map through it I just get "Can't read map of undefined". I think the problem is that it's running...

I'm trying to wrap my head around using hooks and I'm running into a repeating problem.  In the example I've linked below, I have a useEffect hook that's sorting an array.  The sorting order is determined by a state value and I have a...

I'd like to scroll to a given horizontal position in an element immediately after it's rendered by React. For context, I'm using Next.js with server-side rendering, so useLayoutEffect isn't an option.  export default function WideElem...

I want to use useEffect to fire 2 functions (which are redux actions creators) - one function when component mounts, and the other one on unmount, like so:  // ...  function MyComp(props) {   function handleSelectItem(itemId) {     const data = props...

I am trying to set an error message for a registration form but because I am using material UI, I had to use the functional component for my project. I was following a tutorial on youtube but the guy was using a class component. I managed to convert...