Question

我使用API“ https://www.definitions.net/definitions_api.php”制作了react.js应用。当我记录data.result时，它输出正确的结果数组，但是当我通过状态映射时，出现以下错误：“对象作为React子对象无效（找到：带有键{}的对象）。如果您的意思是要呈现子级集合，请改用数组。”

//states
  const [definition, setDefinition] = useState([])
  const [search, setSearch] = useState('')
  const [query, setQuery] = useState('')

  useEffect(() => {
    getDef()
   }, [query])


//FETCH
  const getDef = async () => {
  const response = await fetch(`....`)
  const data = await response.json()
  setDefinition(data.result);

//handle input
  const updateSearch = e => {
    setSearch(e.target.value)

  }

//get the final query onSubmit
const getQuery = e =>{
  e.preventDefault()
  setQuery(search)
  setSearch('')
}


 return (

  { definition && definition.map(item => (
       <Definition term={item.term} 
                  partofspeech = {item.partofspeech}
                  definition={item.definition} 
                  example = {item.example}                 
             />

            )
         )
        }

  );

在“定义”组件中，我分解了道具：

function Definition({term, partofspeech, definition, example}) {
    return (
        <div className="definition">
            <h4>{term} ({partofspeech})</h4>
              <p>{definition}</p>
               <p>{example}</p>

        </div>
    )
}

欢迎您的帮助，谢谢。

Answer 1

尝试一下，当您循环组件循环而没有根元素的定义时，它将导致错误

const Component = () => {
  ....
  return (
    <Fragment>
      { definition && definition.map(item => (
       <Definition term={item.term} 
                  partofspeech = {item.partofspeech}
                  definition={item.definition} 
                  example = {item.example}                 
             />

            )
         )
        }

  )
    </Fragment>
  )
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>

Answer 2

作为回报，您既有({})又有圆形和卷曲，可以将两者都删除，应该直接返回

return definition && definition.map(item => (
       <Definition term={item.term} 
            partofspeech = {item.partofspeech}
            definition={item.definition} 
            example = {item.example}                 
        />
    ));

简短代码段，您可以运行它并查看：

const { useState } = React;

const App = () => {

  const [users,setUsers] = useState(['Vivek' , 'Darshita', 'Darshvi' , 'Coming..']);

  return users.map(user => <p>{user}</p>);
}

ReactDOM.render(<App />, document.getElementById('react-root'));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.4/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.4/umd/react-dom.production.min.js"></script>
<div id="react-root"></div>

React.js错误：“对象作为React子对象无效（找到：带有键{}的对象）。”

2 个答案: