<div style="color: #abb2bf; background-color: #282c34; font-family: Consolas, 'Courier New', monospace; font-size: 14px; line-height: 19px; white-space: pre;">
<div>&nbsp;&nbsp;&nbsp;&nbsp;<span style="color: #61afef;">useEffect</span>(()&nbsp;<span style="color: #c678dd;">=&gt;</span>&nbsp;{&nbsp;&nbsp;<span style="color: #5c6370; font-style: italic;">//&nbsp;componentDidMount,&nbsp;componentDidUpdate&nbsp;=&nbsp;합쳐놓았다고&nbsp;생각</span></div>
<div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;console.<span style="color: #61afef;">log</span>(<span style="color: #98c379;">'랜덤'</span>)</div>
<div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;interval.<span style="color: #e06c75;">current</span>&nbsp;<span style="color: #56b6c2;">=</span>&nbsp;<span style="color: #56b6c2;">setInterval</span>(changeHand,&nbsp;<span style="color: #d19a66;">100</span>)</div>
<div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="color: #c678dd;">return</span>&nbsp;()&nbsp;<span style="color: #c678dd;">=&gt;</span>&nbsp;{&nbsp;&nbsp;<span style="color: #5c6370; font-style: italic;">//&nbsp;componentWillUnmount</span></div>
<div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;console.<span style="color: #61afef;">log</span>(<span style="color: #98c379;">'랜덤종료'</span>)</div>
<div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="color: #56b6c2;">clearInterval</span>(interval.<span style="color: #e06c75;">current</span>)</div>
<div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}</div>
<div>&nbsp;&nbsp;&nbsp;&nbsp;},&nbsp;[imgCoord])&nbsp;&nbsp;<span style="color: #5c6370; font-style: italic;">// componentDidUpdate</span></div>
</div>
<p>componentwillMount가 헷갈리는게</p>
<p>componentDidMount, componentDidUpdate 이후에 바로 실행이 되는건가요~?</p>
<p>아니면 componentDidUpdate가 되면서 기존 컴포넌트가 리렌더링 될 때 일어나나요? 궁금합니다.</p>

<p>새로운 useEffect가 실행되기 직전에 발생합니다.</p>

<p><span style="color: #000a12; font-family: 'Noto Sans KR', -apple-system, system-ui, BlinkMacSystemFont, 'Apple SD Gothic Neo', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif, Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', Helvetica; font-size: 16px; background-color: #ffffff;">useEffect에서 componentwillUnMount인데 오타가 났네요...&nbsp;</span><span style="background-color: #ffffff; color: #000a12; font-family: 'Noto Sans KR', -apple-system, system-ui, BlinkMacSystemFont, 'Apple SD Gothic Neo', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif, Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', Helvetica; font-size: 16px;">useEffect의 작업이 끝난후 바로 return이 실행되나요?</span></p>

Cộng đồng Hỏi & Đáp của Inflearn

useEffect 질문있습니다.