javascript - 更新状态 |对象不可迭代(无法读取属性 Symbol(Symbol.iterator))

Question

我有以下 JSX -

 <FormGroup>
                <Label for="exampleEmail" style={{fontWeight:"bold"}}>What is your e-mail address?</Label>
                <Input type="email" name="email" id="exampleEmail" onChange={(e)=>setStateForProperties(e)} />
            </FormGroup>
            <FormGroup>
                <Label for="examplePassword" style={{fontWeight:"bold"}}>What is your password?</Label>
                <Input type="password" name="password" id="examplePassword" onChange={(e)=>setStateForProperties(e)}/>
 </FormGroup>

国家声明-

  const iLoginCreds ={
    userName:'',
    password:''
  }
  const [loginCreds, setLoginCredentials] = useState(iLoginCreds)

onChange 方法改变状态-

  function setStateForProperties(e)
  {
    alert(e.target.id);
    switch (e.target.id) {
      case 'exampleEmail':
        setLoginCredentials(...loginCreds,{
          userName:e.target.value
        
        });
            
        break;

        case 'examplePassword':
        setLoginCredentials(... loginCreds,{
          password:e.target.value
        });
    
      default:
        break;
    }
    console.log(loginCreds);
  }

错误-

当我在文本框中写任何东西时(在 onchange 事件触发时)，我收到一个错误 -

TypeError: object is not iterable (cannot read property Symbol(Symbol.iterator))

Answer 1

您需要破坏以前的对象属性，并在与新对象合并后返回一个新对象。

setLoginCredentials({ ...loginCreds, ...{userName:e.target.value} })