ES6 destructuring within a return statement

问题

Is it possible to destructure an object while returning it at the same time. For example, to change this code:

const mapStateToProps = ({ newItem }) =>{
  const { id, name, price } = newItem;
  return { id, name, price };
}

To something like this:

const mapStateToProps = ({ newItem }) =>{
  return { id, name, price } = newItem;
}

回答1:

No, it's not possible.

(Disclaimer: your syntax works and does both destructuring and returning, but it is equivalent to

({ id, name, price } = newItem); // assigns global variables
return newItem;

which is probably not what you wanted)

To do what you want (which I assume is creating a new object), you need to use an object literal (potentially with shorthand property notation). See also One-liner to take some properties from object in ES 6:

const mapStateToProps = ({newItem: {id, name, price}}) => ({id, name, price});

回答2:

In ES6 you can also do the following, if you want to pass all the newItem keys

const mapStateToProps = ({ newItem }) => ({ ...newItem });

来源：https://stackoverflow.com/questions/41794086/es6-destructuring-within-a-return-statement