How to destructure from an object and keep the same object?

Question

I'd like to add an event listener to a field, such as this

field.addEventListener("keyup", (event) => {
  if (event.keyCode === 13) {
      event.preventDefault();
      // do something
  }
});

Is there a clean way to keep event and to destructure keyCode from it, because I need both?

Answer 1

You can destructure the object in a new const variable.

field.addEventListener("keyup", (event) => {
  const { keyCode } = event;
  if (keyCode === 13) {
      event.preventDefault();
      // do something
  }
});

Answer 2

You could destructure to object, in the parameter list, the object is no gone, but you could pull it from the arguments object .

Which does not make the code nicer ...

 function perform({ baz }) { console.log(baz); console.log(arguments[0]); } var object = { foo: 'bar', baz: 42 }; perform(object);

Answer 3

You could something like,

const use = (i, cb) => cb(i, i)

use(doSomething(), (event, { keyCode }) => {
    // 
});

Answer 4

Well, unfortunately, no, not the way I think you mean. You could do something like this:

field.addEventListener("keyup", event => {
  // whatever you want to destructure
  const {keyCode} = event; 
  if (keyCode === 13) {
      event.preventDefault();
      // do something
  }
});

This probably isn't that helpful, though, as I'm sure you want to destructure in the parameter list of your event handler.