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Question

Warning: Encountered two children with the same key, `[object Object]`. Keys should be unique so that components maintain their identity across updates. Non-unique keys may cause children to be duplicated and/or omitted — the behavior is unsupported and could change in a future version. 이렇게 오류가 납니다. 다른분 질문을 보니 key에서 createdAt이 문제인 것 같은데 어떻게 수정을 해야할 지 모르겟습니다ㅠ return ( < div > < Card key = { + post .createdAt} cover = { post .img && < img alt = "example" src = { post .img} /> } actions = {[ < Icon type = "retweet" key = "retweet" /> , ////////////////////////// PostCard .propTypes = { post : PropTypes . shape ( { User : PropTypes . object , content : PropTypes .string, img : PropTypes .string, createdAt : PropTypes . object , } ), };

제로초(조현영) · Answer

지금 Card쪽을 보고계신데 Card가 아니라 PostCard를 보셔야 합니다. PostCard가 쓰이는 곳이요.

생글탱글 · Answer

맞는 것 같아요... ---> index.js:1 Warning: Failed prop type: Invalid prop `post.createdAt` of type `string` supplied to `PostCard`, expected `object`.     in PostCard (at pages/index.js:23) ---> index.js:1 Warning: Encountered two children with the same key, `[object Object]`. Keys should be unique so that components maintain their identity across updates. Non-unique keys may cause children to be duplicated and/or omitted &mdash; the behavior is unsupported and could change in a future version. PostCard .propTypes = { post : PropTypes . shape ( { User : PropTypes . object , content : PropTypes .string, img : PropTypes .string, createdAt : PropTypes . object , } ), };

제로초(조현영) · Answer

에러메시지의 위치가 Card가 맞나요??

생글탱글 · Answer

createdAt 2020-04-12T08:32:59.000Z PostCard.js:39 createdAt 2020-04-12T08:32:01.000Z PostCard.js:39 createdAt 2020-04-10T07:20:10.000Z PostCard.js:39 createdAt 2020-04-10T07:20:00.000Z PostCard.js:39 createdAt 2020-04-10T07:04:42.000Z 전부 다른 값이 나옵니다. 그리고  post.id로 했는데도 같은 에러가 나요ㅠㅠ Warning: Encountered two children with the same key, `[object Object]`. Keys should be unique so that components maintain their identity across updates. Non-unique keys may cause children to be duplicated and/or omitted &mdash; the behavior is unsupported and could change in a future version. < Card key = { + post . id } cover = { post .img && < img alt = "example" src = { post .img} /> } actions = {[

제로초(조현영) · Answer

위에서 console.log('createdAt', post.createdAt)을 먼저 해서 값을 확인해보세요. 고유하기만 하면 되므로 post.id 이런 고유값이 더 낫습니다.