如何从箭头函数返回值？

Question

I'm trying to return string from those two functions and attach it to my object parameters. Any idea how to make it return the string?

 const getEmail = () => {
    ls.get('email').then((email) => {
        if (email == null) {
            return '';
        }
        return email;
    })
}

 const getPassword = () => {
    ls.get('password').then((password) => {
      if (password == null) {
            return '';
        }
        return password;
    })
}

const INITIAL_STATE = {
     email: getEmail(),
     password: getPassword(),
     user: null,
     error: '',
     loading: false
     };

Answer 1

You can't return a string from the future, but you can return the promise, store it on your state and then reuse it!

class Example extends Component {
  state = {
    email: '';
  }

  getEmail = () => {
    ls.get('email').then((email) => {
      if (email == null) {
        this.setState({ email: ''});
      }
      this.setState({ email });
    })
  }

  render()...
}