react-TypeError：無法讀取未定義的屬性'trim'

Question

我不確定我在做什么錯。

class Login extends Component {

    render() {
        const username = "me@domain.com  ";
        console.log(username)
        const password = this.refs.password;
        const creds = {
            username: username.value.trim(),
            password: password.value.trim()
        };
        const errorMessage  = this.props;

        return ( ... ) } }

控制台顯示“ me@domain.com”，但username: username.value.trim()錯誤

  11 | console.log(username)
  12 | const password = this.refs.password;
  13 | const creds = {
> 14 |     username: username.value.trim(),
  15 |     password: password.value.trim()
  16 | };
  17 | const errorMessage  = this.props;

Answer 1

username.value.trim()

username本身是一個字符串，您無需從中獲取價值。 修剪一下

const creds = {
        username: username.trim(),
        password: password.value.trim()
    };

Answer 2

username不是object而是字符串，因此您將編寫

const username = "me@domain.com  ";
const creds = {
        username: username.trim(),
        password: password.trim()
    };

同樣，您不應該使用string refs因為它們已被棄用。