Why Does count Not Increment Correctly on Multiple Clicks?
Q53 :- What is the output of the following code snippet when the "Click me" button is clicked twice? function App() { const [count, setCount] = React.useState(0);
return (
You clicked {count} times
<button onClick={() => setCount(count + 1)}>Click meRight Ans : -
Each time the button is clicked:
- The event handler runs:
setCount(count + 1). - React schedules a re-render with the updated state.
- However, the state update is not immediate. The value of
countinside the event handler is the value from the last render. - Since
countdoes not update synchronously, clicking twice in quick succession causes both clicks to use the old stale state value.
Step-by-step breakdown:
| Click # | Current count | Expression (setCount(count + 1)) |
Updated count |
|---|---|---|---|
| 0 (initial) | 0 | - | 0 |
| 1st Click | 0 | setCount(0 + 1) |
1 |
| 2nd Click | 0 (stale) | setCount(0 + 1) |
1 (not 2!) |
Thus, after two clicks, count will be 1 instead of 2.
I wanted to work on this issue so please assign this task to me.
Thank you.
Try to add a use effect() hook to run everytime count changes so it will probably look something like this
useEffect() { Update count code here , [count]}
Basically the useEffect hook will mount everytime count changes and update count even with multiple clicks
You may also be able to add prev + 1 so it saves the count and then adds 1