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useEffect calling api's couple of times reactjs

I have this useEffect function in react component. I am calling api videoGridState here.
Now what is happening here it is calling my api 2 times one at intitial page reaload and second one when count is changing. I want it to be called single time when page reloads. But also when streamSearchText changes
const [count, setCount] = useState(0);
const [streamSearchText, setStreamSearchText] = useState("");
useEffect(() => {
videoGridState();
}, [count]);
useEffect(() => {
const delayDebounceFn = setTimeout(() => {
setCount(count + 1);
}, 1000);
return () => clearTimeout(delayDebounceFn);
}, [streamSearchText]);
How can I do that?

The main issue is that you have two useEffect calls, and so they're each handled, and the second triggers the first (after a delay), resulting in the duplication.
As I understand it, your goal is:
Run videoGridState immediately on mount, and
Run it again after a delay of 1000ms whenever streamSearchText changes
That turns out to be surprisingly awkward to do. I'd probably end up using a ref for it:
const firstRef = useRef(true);
const [streamSearchText, setStreamSearchText] = useState("");
useEffect(() => {
if (firstRef.current) {
// Mount
videoGridState();
firstRef.current = false;
} else {
// `streamSearchText` change
const timer = setTimeout(() => {
videoGridState();
}, 1000);
return () => clearTimeout(timer);
}
}, [streamSearchText]);
Live Example:
const { useState, useRef, useEffect } = React;
function videoGridState() {
console.log("videoGridState ran");
}
const Example = () => {
const firstRef = useRef(true);
const [streamSearchText, setStreamSearchText] = useState("");
useEffect(() => {
if (firstRef.current) {
// Mount
videoGridState();
firstRef.current = false;
} else {
// `streamSearchText` change
const timer = setTimeout(() => {
videoGridState();
}, 1000);
return () => clearTimeout(timer);
}
}, [streamSearchText]);
return <div>
<label>
Search text:{" "}
<input
type="text"
value={streamSearchText}
onChange={(e) => setStreamSearchText(e.currentTarget.value)}
/>
</label>
</div>;
};
const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(<Example />);
<div id="root"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/18.1.0/umd/react.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/18.1.0/umd/react-dom.development.js"></script>
You could also do the query immediately when streamSearchText is "", but that would happen every time streamSearchText was "", not just on mount. That may be good enough, depending on how rigorous you need to be.
Additionally, though, if you're still seeing something happen "on mount" twice, you may be running a development copy of the libraries with React.StrictMode around your app (the default in many scaffolding systems). See this question's answers for details on how React.StrictMode may mount your component more than once and throw in other seeming surprises.

Your following useEffect() function makes this behaviour to happen:
useEffect(() => {
const delayDebounceFn = setTimeout(() => {
setCount(count + 1);
}, 1000);
return () => clearTimeout(delayDebounceFn);
}, [streamSearchText]);
Since it runs initially but called setCount() which updates the state, and forces a re-render of the component which in turn runs the first useEffect() since that has [count] in the dependency array.
And hence the cycle continues for the [count]

const Example = () => {
const { useState, useRef, useEffect } = React;
// Any async function or function that returns a promise
function myDownloadAsyncFunction(data) {
console.log("222222222222222222222")
return new Promise((resolve) => setTimeout(resolve, 1000));
}
function DownloadButton() {
const [queue, setQueue] = useState(Promise.resolve());
onClickDownload = () => {
setQueue(queue
.then(() => myDownloadAsyncFunction('My data'))
.catch((err) => {console.error(err)})
)
}
return (
<button onClick={onClickDownload()}>Download</button>
);
}
}
const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(<Example />);
<div id="root"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/18.1.0/umd/react.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/18.1.0/umd/react-dom.development.js"></script>

useRef error continues after component unmounts [duplicate]

I don't understand why is when I use setTimeout function my react component start to infinite console.log. Everything is working, but PC start to lag as hell.
Some people saying that function in timeout changing my state and that rerender component, that sets new timer and so on. Now I need to understand how to clear it's right.
export default function Loading() {
// if data fetching is slow, after 1 sec i will show some loading animation
const [showLoading, setShowLoading] = useState(true)
let timer1 = setTimeout(() => setShowLoading(true), 1000)
console.log('this message will render every second')
return 1
}
Clear in different version of code not helping to:
const [showLoading, setShowLoading] = useState(true)
let timer1 = setTimeout(() => setShowLoading(true), 1000)
useEffect(
() => {
return () => {
clearTimeout(timer1)
}
},
[showLoading]
)

Defined return () => { /*code/* } function inside useEffect runs every time useEffect runs (except first render on component mount) and on component unmount (if you don't display component any more).
This is a working way to use and clear timeouts or intervals:
Sandbox example.
import { useState, useEffect } from "react";
const delay = 5;
export default function App() {
const [show, setShow] = useState(false);
useEffect(
() => {
let timer1 = setTimeout(() => setShow(true), delay * 1000);
// this will clear Timeout
// when component unmount like in willComponentUnmount
// and show will not change to true
return () => {
clearTimeout(timer1);
};
},
// useEffect will run only one time with empty []
// if you pass a value to array,
// like this - [data]
// than clearTimeout will run every time
// this value changes (useEffect re-run)
[]
);
return show ? (
<div>show is true, {delay}seconds passed</div>
) : (
<div>show is false, wait {delay}seconds</div>
);
}
If you need to clear timeouts or intervals in another component:
Sandbox example.
import { useState, useEffect, useRef } from "react";
const delay = 1;
export default function App() {
const [counter, setCounter] = useState(0);
const timer = useRef(null); // we can save timer in useRef and pass it to child
useEffect(() => {
// useRef value stored in .current property
timer.current = setInterval(() => setCounter((v) => v + 1), delay * 1000);
// clear on component unmount
return () => {
clearInterval(timer.current);
};
}, []);
return (
<div>
<div>Interval is working, counter is: {counter}</div>
<Child counter={counter} currentTimer={timer.current} />
</div>
);
}
function Child({ counter, currentTimer }) {
// this will clearInterval in parent component after counter gets to 5
useEffect(() => {
if (counter < 5) return;
clearInterval(currentTimer);
}, [counter, currentTimer]);
return null;
}
Article from Dan Abramov.

The problem is you are calling setTimeout outside useEffect, so you are setting a new timeout every time the component is rendered, which will eventually be invoked again and change the state, forcing the component to re-render again, which will set a new timeout, which...
So, as you have already found out, the way to use setTimeout or setInterval with hooks is to wrap them in useEffect, like so:
React.useEffect(() => {
const timeoutID = window.setTimeout(() => {
...
}, 1000);
return () => window.clearTimeout(timeoutID );
}, []);
As deps = [], useEffect's callback will only be called once. Then, the callback you return will be called when the component is unmounted.
Anyway, I would encourage you to create your own useTimeout hook so that you can DRY and simplify your code by using setTimeout declaratively, as Dan Abramov suggests for setInterval in Making setInterval Declarative with React Hooks, which is quite similar:
function useTimeout(callback, delay) {
const timeoutRef = React.useRef();
const callbackRef = React.useRef(callback);
// Remember the latest callback:
//
// Without this, if you change the callback, when setTimeout kicks in, it
// will still call your old callback.
//
// If you add `callback` to useEffect's deps, it will work fine but the
// timeout will be reset.
React.useEffect(() => {
callbackRef.current = callback;
}, [callback]);
// Set up the timeout:
React.useEffect(() => {
if (typeof delay === 'number') {
timeoutRef.current = window.setTimeout(() => callbackRef.current(), delay);
// Clear timeout if the components is unmounted or the delay changes:
return () => window.clearTimeout(timeoutRef.current);
}
}, [delay]);
// In case you want to manually clear the timeout from the consuming component...:
return timeoutRef;
}
const App = () => {
const [isLoading, setLoading] = React.useState(true);
const [showLoader, setShowLoader] = React.useState(false);
// Simulate loading some data:
const fakeNetworkRequest = React.useCallback(() => {
setLoading(true);
setShowLoader(false);
// 50% of the time it will display the loder, and 50% of the time it won't:
window.setTimeout(() => setLoading(false), Math.random() * 4000);
}, []);
// Initial data load:
React.useEffect(fakeNetworkRequest, []);
// After 2 second, we want to show a loader:
useTimeout(() => setShowLoader(true), isLoading ? 2000 : null);
return (<React.Fragment>
<button onClick={ fakeNetworkRequest } disabled={ isLoading }>
{ isLoading ? 'LOADING... 📀' : 'LOAD MORE 🚀' }
</button>
{ isLoading && showLoader ? <div className="loader"><span className="loaderIcon">📀</span></div> : null }
{ isLoading ? null : <p>Loaded! ✨</p> }
</React.Fragment>);
}
ReactDOM.render(<App />, document.querySelector('#app'));
body,
button {
font-family: monospace;
}
body, p {
margin: 0;
}
#app {
display: flex;
flex-direction: column;
align-items: center;
min-height: 100vh;
}
button {
margin: 32px 0;
padding: 8px;
border: 2px solid black;
background: transparent;
cursor: pointer;
border-radius: 2px;
}
.loader {
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100vh;
display: flex;
align-items: center;
justify-content: center;
font-size: 128px;
background: white;
}
.loaderIcon {
animation: spin linear infinite .25s;
}
#keyframes spin {
from { transform:rotate(0deg) }
to { transform:rotate(360deg) }
}
<script src="https://unpkg.com/react#16.7.0-alpha.0/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom#16.7.0-alpha.0/umd/react-dom.development.js"></script>
<div id="app"></div>
Apart from producing simpler and cleaner code, this allows you to automatically clear the timeout by passing delay = null and also returns the timeout ID, in case you want to cancel it yourself manually (that's not covered in Dan's posts).
If you are looking for a similar answer for setInterval rather than setTimeout, check this out: https://stackoverflow.com/a/59274004/3723993.
You can also find declarative version of setTimeout and setInterval, useTimeout and useInterval, a few additional hooks written in TypeScript in https://www.npmjs.com/package/#swyg/corre.

Your computer was lagging because you probably forgot to pass in the empty array as the second argument of useEffect and was triggering a setState within the callback. That causes an infinite loop because useEffect is triggered on renders.
Here's a working way to set a timer on mount and clearing it on unmount:
function App() {
React.useEffect(() => {
const timer = window.setInterval(() => {
console.log('1 second has passed');
}, 1000);
return () => { // Return callback to run on unmount.
window.clearInterval(timer);
};
}, []); // Pass in empty array to run useEffect only on mount.
return (
<div>
Timer Example
</div>
);
}
ReactDOM.render(
<div>
<App />
</div>,
document.querySelector("#app")
);
<script src="https://unpkg.com/react#16.7.0-alpha.0/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom#16.7.0-alpha.0/umd/react-dom.development.js"></script>
<div id="app"></div>

I wrote a react hook to never again have to deal with timeouts.
works just like React.useState():
New answer
const [showLoading, setShowLoading] = useTimeoutState(false)
// sets loading to true for 1000ms, then back to false
setShowLoading(true, { timeout: 1000})
export const useTimeoutState = <T>(
defaultState: T
): [T, (action: SetStateAction<T>, opts?: { timeout: number }) => void] => {
const [state, _setState] = useState<T>(defaultState);
const [currentTimeoutId, setCurrentTimeoutId] = useState<
NodeJS.Timeout | undefined
>();
const setState = useCallback(
(action: SetStateAction<T>, opts?: { timeout: number }) => {
if (currentTimeoutId != null) {
clearTimeout(currentTimeoutId);
}
_setState(action);
const id = setTimeout(() => _setState(defaultState), opts?.timeout);
setCurrentTimeoutId(id);
},
[currentTimeoutId, defaultState]
);
return [state, setState];
};
Old answer
const [showLoading, setShowLoading] = useTimeoutState(false, {timeout: 5000})
// will set show loading after 5000ms
setShowLoading(true)
// overriding and timeouts after 1000ms
setShowLoading(true, { timeout: 1000})
Setting multiple states will refresh the timeout and it will timeout after the same ms that the last setState set.
Vanilla js (not tested, typescript version is):
import React from "react"
// sets itself automatically to default state after timeout MS. good for setting timeouted states for risky requests etc.
export const useTimeoutState = (defaultState, opts) => {
const [state, _setState] = React.useState(defaultState)
const [currentTimeoutId, setCurrentTimeoutId] = React.useState()
const setState = React.useCallback(
(newState: React.SetStateAction, setStateOpts) => {
clearTimeout(currentTimeoutId) // removes old timeouts
newState !== state && _setState(newState)
if (newState === defaultState) return // if already default state, no need to set timeout to set state to default
const id = setTimeout(
() => _setState(defaultState),
setStateOpts?.timeout || opts?.timeout
)
setCurrentTimeoutId(id)
},
[currentTimeoutId, state, opts, defaultState]
)
return [state, setState]
}
Typescript:
import React from "react"
interface IUseTimeoutStateOptions {
timeout?: number
}
// sets itself automatically to default state after timeout MS. good for setting timeouted states for risky requests etc.
export const useTimeoutState = <T>(defaultState: T, opts?: IUseTimeoutStateOptions) => {
const [state, _setState] = React.useState<T>(defaultState)
const [currentTimeoutId, setCurrentTimeoutId] = React.useState<number | undefined>()
// todo: change any to React.setStateAction with T
const setState = React.useCallback(
(newState: React.SetStateAction<any>, setStateOpts?: { timeout?: number }) => {
clearTimeout(currentTimeoutId) // removes old timeouts
newState !== state && _setState(newState)
if (newState === defaultState) return // if already default state, no need to set timeout to set state to default
const id = setTimeout(
() => _setState(defaultState),
setStateOpts?.timeout || opts?.timeout
) as number
setCurrentTimeoutId(id)
},
[currentTimeoutId, state, opts, defaultState]
)
return [state, setState] as [
T,
(newState: React.SetStateAction<T>, setStateOpts?: { timeout?: number }) => void
]
}```

export const useTimeout = () => {
const timeout = useRef();
useEffect(
() => () => {
if (timeout.current) {
clearTimeout(timeout.current);
timeout.current = null;
}
},
[],
);
return timeout;
};
You can use simple hook to share timeout logic.
const timeout = useTimeout();
timeout.current = setTimeout(your conditions)

Trigger api every 10 seconds:
useEffect(() => {
const timer = window.setInterval(() => {
// function of api call
}, 1000);
return () => {
window.clearInterval(timer);
}
}, [])
if any state change:
useEffect(() => {
// add condition to state if needed
const timer = window.setInterval(() => {
// function of api call
}, 1000);
return () => {
window.clearInterval(timer);
}
}, [state])

If your timeout is in the "if construction" try this:
useEffect(() => {
let timeout;
if (yourCondition) {
timeout = setTimeout(() => {
// your code
}, 1000);
} else {
// your code
}
return () => {
clearTimeout(timeout);
};
}, [yourDeps]);

const[seconds, setSeconds] = useState(300);
function TimeOut() {
useEffect(() => {
let interval = setInterval(() => {
setSeconds(seconds => seconds -1);
}, 1000);
return() => clearInterval(interval);
}, [])
function reset() {
setSeconds(300);
}
return (
<div>
Count Down: {seconds} left
<button className="button" onClick={reset}>
Reset
</button>
</div>
)
}
Make sure to import useState and useEffect. Also, add the logic to stop the timer at 0.

If you want to make a button like "start" then using "useInterval" hook may not be suitable since react doesn't allow you call hooks other than at the top of component.
export default function Loading() {
// if data fetching is slow, after 1 sec i will show some loading animation
const [showLoading, setShowLoading] = useState(true)
const interval = useRef();
useEffect(() => {
interval.current = () => setShowLoading(true);
}, [showLoading]);
// make a function like "Start"
// const start = setInterval(interval.current(), 1000)
setInterval(() => interval.current(), 1000);
console.log('this message will render every second')
return 1
}

In case of Intervals to avoid continual attaching (mounting) and detaching (un-mounting) the setInterval method to the event-loop by the use of useEffect hook in the examples given by others, you may instead benefit the use of useReducer.
Imagine a scenario where given seconds and minutes you shall count the time down...
Below we got a reducer function that does the count-down logic.
const reducer = (state, action) => {
switch (action.type) {
case "cycle":
if (state.seconds > 0) {
return { ...state, seconds: state.seconds - 1 };
}
if (state.minutes > 0) {
return { ...state, minutes: state.minutes - 1, seconds: 60 };
}
case "newState":
return action.payload;
default:
throw new Error();
}
}
Now all we have to do is dispatch the cycle action in every interval:
const [time, dispatch] = useReducer(reducer, { minutes: 0, seconds: 0 });
const { minutes, seconds } = time;
const interval = useRef(null);
//Notice the [] provided, we are setting the interval only once (during mount) here.
useEffect(() => {
interval.current = setInterval(() => {
dispatch({ type: "cycle" });
}, 1000);
// Just in case, clear interval on component un-mount, to be safe.
return () => clearInterval(interval.current);
}, []);
//Now as soon as the time in given two states is zero, remove the interval.
useEffect(() => {
if (!minutes && !seconds) {
clearInterval(interval.current);
}
}, [minutes, seconds]);
// We could have avoided the above state check too, providing the `clearInterval()`
// inside our reducer function, but that would delay it until the next interval.

React interval using old state inside of useEffect

I ran into a situation where I set an interval timer from inside useEffect. I can access component variables and state inside the useEffect, and the interval timer runs as expected. However, the timer callback doesn't have access to the component variables / state. Normally, I would expect this to be an issue with "this". However, I do not believe "this" is the the case here. No puns were intended. I have included a simple example below:
import React, { useEffect, useState } from 'react';
const App = () => {
const [count, setCount] = useState(0);
const [intervalSet, setIntervalSet] = useState(false);
useEffect(() => {
if (!intervalSet) {
setInterval(() => {
console.log(`count=${count}`);
setCount(count + 1);
}, 1000);
setIntervalSet(true);
}
}, [count, intervalSet]);
return <div></div>;
};
export default App;
The console outputs only count=0 each second. I know that there's a way to pass a function to the setCount which updates current state and that works in this trivial example. However, that was not the point I was trying to make. The real code is much more complex than what I showed here. My real code looks at current state objects that are being managed by async thunk actions. Also, I am aware that I didn't include the cleanup function for when the component dismounts. I didn't need that for this simple example.

The first time you run the useEffect the intervalSet variable is set to true and your interval function is created using the current value (0).
On subsequent runs of the useEffect it does not recreate the interval due to the intervalSet check and continues to run the existing interval where count is the original value (0).
You are making this more complicated than it needs to be.
The useState set function can take a function which is passed the current value of the state and returns the new value, i.e. setCount(currentValue => newValue);
An interval should always be cleared when the component is unmounted otherwise you will get issues when it attempts to set the state and the state no longer exists.
import React, { useEffect, useState } from 'react';
const App = () => {
// State to hold count.
const [count, setCount] = useState(0);
// Use effect to create and clean up the interval
// (should only run once with current dependencies)
useEffect(() => {
// Create interval get the interval ID so it can be cleared later.
const intervalId = setInterval(() => {
// use the function based set state to avoid needing count as a dependency in the useEffect.
// this stops the need to code logic around stoping and recreating the interval.
setCount(currentCount => {
console.log(`count=${currentCount}`);
return currentCount + 1;
});
}, 1000);
// Create function to clean up the interval when the component unmounts.
return () => {
if (intervalId) {
clearInterval(intervalId);
}
}
}, [setCount]);
return <div></div>;
};
export default App;
You can run the code and see this working below.
const App = () => {
// State to hold count.
const [count, setCount] = React.useState(0);
// Use effect to create and clean up the interval
// (should only run once with current dependencies)
React.useEffect(() => {
// Create interval get the interval ID so it can be cleared later.
const intervalId = setInterval(() => {
// use the function based set state to avoid needing count as a dependency in the useEffect.
// this stops the need to code logic around stoping and recreating the interval.
setCount(currentCount => {
console.log(`count=${currentCount}`);
return currentCount + 1;
});
}, 1000);
// Create function to clean up the interval when the component unmounts.
return () => {
if (intervalId) {
clearInterval(intervalId);
}
}
}, [setCount]);
return <div></div>;
};
ReactDOM.render(<App />, document.getElementById('app'))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.1/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.1/umd/react-dom.production.min.js"></script>
<div id="app"></div>

If you need a more complex implementation as mention in your comment on another answer, you should try using a ref perhaps. For example, this is a custom interval hook I use in my projects. You can see there is an effect that updates callback if it changes.
This ensures you always have the most recent state values and you don't need to use the custom updater function syntax like setCount(count => count + 1).
const useInterval = (callback, delay) => {
const savedCallback = useRef()
useEffect(() => {
savedCallback.current = callback
}, [callback])
useEffect(() => {
if (delay !== null) {
const id = setInterval(() => savedCallback.current(), delay)
return () => clearInterval(id)
}
}, [delay])
}
// Usage
const App = () => {
useInterval(() => {
// do something every second
}, 1000)
return (...)
}
This is a very flexible option you could use. However, this hook assumes you want to start your interval when the component mounts. Your code example leads me to believe you want this to start based on the state change of the intervalSet boolean. You could update the custom interval hook, or implement this in your component.
It would look like this in your example:
const useInterval = (callback, delay, initialStart = true) => {
const [start, setStart] = React.useState(initialStart)
const savedCallback = React.useRef()
React.useEffect(() => {
savedCallback.current = callback
}, [callback])
React.useEffect(() => {
if (start && delay !== null) {
const id = setInterval(() => savedCallback.current(), delay)
return () => clearInterval(id)
}
}, [delay, start])
// this function ensures our state is read-only
const startInterval = () => {
setStart(true)
}
return [start, startInterval]
}
const App = () => {
const [countOne, setCountOne] = React.useState(0);
const [countTwo, setCountTwo] = React.useState(0);
const incrementCountOne = () => {
setCountOne(countOne + 1)
}
const incrementCountTwo = () => {
setCountTwo(countTwo + 1)
}
// Starts on component mount by default
useInterval(incrementCountOne, 1000)
// Starts when you call `startIntervalTwo(true)`
const [intervalTwoStarted, startIntervalTwo] = useInterval(incrementCountTwo, 1000, false)
return (
<div>
<p>started: {countOne}</p>
<p>{intervalTwoStarted ? 'started' : <button onClick={startIntervalTwo}>start</button>}: {countTwo}</p>
</div>
);
};
ReactDOM.render(<App />, document.getElementById('app'))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.1/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.1/umd/react-dom.production.min.js"></script>
<div id="app"></div>

The problem is the interval is created only once and keeps pointing to the same state value. What I would suggest - move firing the interval to separate useEffect, so it starts when the component mounts. Store interval in a variable so you are able to restart it or clear. Lastly - clear it with every unmount.
const App = () => {
const [count, setCount] = React.useState(0);
const [intervalSet, setIntervalSet] = React.useState(false);
React.useEffect(() => {
setIntervalSet(true);
}, []);
React.useEffect(() => {
const interval = intervalSet ? setInterval(() => {
setCount((c) => {
console.log(c);
return c + 1;
});
}, 1000) : null;
return () => clearInterval(interval);
}, [intervalSet]);
return null;
};
ReactDOM.render(<App />, document.getElementById("root"));
<script src="https://unpkg.com/react#16/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom#16/umd/react-dom.development.js"></script>
<div id="root"></div>

How make react countdown timer

i'm trying to do countdown timer with react. It will be basically countdown from 10 to 0 and when 0 i will call some function.
i found ideally for me some example: https://codesandbox.io/s/0q453m77nw?from-embed
but it's a class component i wan't to do that with functional component and hooks but i can't.
i tried:
function App() {
const [seconds, setSeconds] = useState(10);
useEffect(() => {
setSeconds(setInterval(seconds, 1000));
}, []);
useEffect(() => {
tick();
});
function tick() {
if (seconds > 0) {
setSeconds(seconds - 1)
} else {
clearInterval(seconds);
}
}
return (
<div className="App">
<div
{seconds}
</div>
</div>
);
}
export default App;
it's count down from 10 to 0 very quickly not in 10 seconds.
where i mistake ?

It appears the multiple useEffect hooks are causing the countdown to run more than once per second.
Here's a simplified solution, where we check the seconds in the useEffect hook and either:
Use setTimeout to update seconds after 1 second, or
Do something else (the function you want to call at the end of the countdown)
There are some downsides to this method, see below.
function App() {
const [seconds, setSeconds] = React.useState(10);
React.useEffect(() => {
if (seconds > 0) {
setTimeout(() => setSeconds(seconds - 1), 1000);
} else {
setSeconds('BOOOOM!');
}
});
return (
<div className="App">
<div>
{seconds}
</div>
</div>
);
}
ReactDOM.render(<App />, document.getElementById('root'))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.12.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.11.0/umd/react-dom.production.min.js"></script>
<div id="root"></div>
Downsides
Using setInterval has the downside that it could be stopped - for example, the component is unmounted, you navigate to a different tab, or close your computer. If the timer requires more robustness, the better alternative would be to store an endTime in the state (like a global store or context) and have your component check the current time against the endTime to calculate the countdown.

Do you care about precision? If so, you don't want setInterval. If you don't care about precision (and you probably don't) then you can schedule a call to tick() on an interval, not the other way around.
const TimeoutComponent extends Component {
constructor(props) {
super(props);
this.state = { countdown: 10 };
this.timer = setInterval(() => this.tick(), props.timeout || 10000);
}
tick() {
const current = this.state.countdown;
if (current === 0) {
this.transition();
} else {
this.setState({ countdown: current - 1 });
}
}
transition() {
clearInterval(this.timer);
// do something else here, presumably.
}
render() {
return <div className="timer">{this.state.countDown}</div>;
}
}

This depends on your logic a little bit. In the current situation your useEffect where you run your tick method is running on every render. You can find a naive example below.
function App() {
const [seconds, setSeconds] = useState(10);
const [done, setDone] = useState(false);
const foo = useRef();
useEffect(() => {
function tick() {
setSeconds(prevSeconds => prevSeconds - 1)
}
foo.current = setInterval(() => tick(), 1000)
}, []);
useEffect(() => {
if (seconds === 0) {
clearInterval(foo.current);
setDone(true);
}
}, [seconds])
return (
<div className="App">
{seconds}
{done && <p>Count down is done.</p>}
</div>
);
}
In the first effect we are doing the countdown. Using callback one for setting state since interval creates a closure. In the second effect we are checking our condition.

Simply use this snippet, As it will also help to memoize the timeout callback.
const [timer, setTimer] = useState(60);
const timeOutCallback = useCallback(() => setTimer(currTimer => currTimer - 1), []);
useEffect(() => {
timer > 0 && setTimeout(timeOutCallback, 1000);
}, [timer, timeOutCallback]);
console.log(timer);
Hope this will help you or somebody else.
Happy Coding!

Unable to access state inside interval

I am unable to access the state within an interval. Here I want to access counter inside interval when the counter gets equal to 10 I want to stop it.
Note: Here I don't want to put an interval inside useEffect because I need to start the interval in a specific time, by handling an event.
export default props => {
const [counter, setCounter] = useState(0);
const startInterval = () => {
const timeout = setInterval(() => {
setCounter(counter + 1);
console.log("counter: ", counter); // alway return 0
if(counter === 10) clearInterval(timeout);
}, 1000);
};
}

As I am seeing here even your setCounter(counter+1) wont update, because of lexical scope. So you have to change it like this:
setCounter(counter => counter + 1);
Also because of lexical scope you wont access counter to check condition, so you have to make a variable and update that inside functional component by asigning counter to it, then check it with if condition.
Complete Code code:
let myCounter = 0;
let timeout = null;
export default CounterApp = props => {
const [counter, setCounter] = useState(0);
// Also don't forget this
useEffect(()=> {
return ()=> clearInterval(timeout);
}, []);
myCounter = counter;
const startInterval = () => {
timeout = setInterval(() => {
setCounter(counter => counter + 1);
console.log("counter: ", myCounter); // counter always return 0 but myCounter the updated value
if(myCounter === 10) clearInterval(timeout);
}, 1000);
};
}

I came across this exact problem not too long ago. Hooks don't work exactly as you'd expect in relation to setInterval. I found the solution on Dan Abramov's blog: You can useRef to combine multiple useEffects. Through his useInterval implementation you can also start and stop the interval by setting the timer to null
import React, { useState, useEffect, useRef } from 'react';
function Counter() {
const [count, setCount] = useState(0);
const [time, setTime] = useState(null); // timer doesn't run initially
useInterval(() => {
// Your custom logic here
setCount(count + 1);
}, time);
return <>
<h1>{count}</h1>
<div onClick={() => setTime(1000)}>Start</div>
<div onClick={() => setTime(null)}>Stop</div>
</>;
}
import React, { useState, useEffect, useRef } from 'react';
function useInterval(callback, delay) {
const savedCallback = useRef();
// Remember the latest callback.
useEffect(() => {
savedCallback.current = callback;
}, [callback]);
// Set up the interval.
useEffect(() => {
function tick() {
savedCallback.current();
}
if (delay !== null) {
let id = setInterval(tick, delay);
return () => clearInterval(id);
}
}, [delay]);
}