(React 18 이전 버전을 기준으로 하고 있습니다.)
function App() {
const [counter1, setCounter1] = useState(0);
const [counter2, setCounter2] = useState(0);
const [counter3, setCounter3] = useState(0);
const [renderCount, setRenderCount] = useState(0);
useEffect(() => {
setRenderCount(renderCount + 1);
}, [counter1, counter2, counter3]);
const handleClick = () => {
setCounter1(counter1 + 1);
setCounter2(counter2 + 1);
setCounter3(counter3 + 1);
}
return (
<div>
<h1>{renderCount}</h1>
<button onClick={handleClick}>Click</button>
<h2>{counter1}</h2>
<h2>{counter2}</h2>
<h2>{counter3}</h2>
</div>
);
}
Q. 버튼 클릭시에 renderCount의 증가 값은?
정답
해설
const handleClick = () => {
setTimeout(() => {
setCounter1(counter1 + 1);
setCounter2(counter2 + 1);
setCounter3(counter3 + 1);
}, 1000);
}
Q. 버튼 클릭시 renderCount의 증가 값은?
정답
해설