This content originally appeared on DEV Community and was authored by yinguzwg-1
import "./styles.css";
import { useRef, useState } from "react";
export default function App() {
const [count, setCount] = useState(0);
const ref = useRef(null);
const handleClick = () => {
setCount(count + 1);
setCount((pre) => pre + 1);
};
return (
<div className="App">
<button onClick={handleClick}>+</button>
<h1>{count}</h1>
<h2>Start editing to see some magic happen!</h2>
</div>
);
}
demo site as following. https://codesandbox.io/p/sandbox/affectionate-merkle-nrfkvh?file=%2Fsrc%2FApp.js%3A1%2C1-17%2C2
when i click the button, the count increased two at one time,but when i change code order in the handleClick function, seem like
const handleClick = () => {
setCount((pre) => pre + 1);
setCount(count + 1);
};
the count increased one at one time.
why? i hope someone can help me to explain this,thank you
This content originally appeared on DEV Community and was authored by yinguzwg-1