JS object destructuring without defining variable names [duplicate]

Question

When destructuring objects in ES6 JS, you can use the { a, b } syntax in order to create new variables, called a and b respectively, from that object. However, as far as I can tell, there is no way to get the keys of the object to automatically create locally-scoped variables with those names. In the following example, I would like to be able to use the hypothetical pseudocode of const {} = args; and it would generate const a and const b automatically.

const bar = { a: 'apple', b: 'ball' };

const foo = (args) => {
  const { a, b } = args;
  console.log(a, b); // Great!
  const {} = args;   // I am aware this isn't valid syntax...
  console.log(a, b)  // Because of course, it doesn't work.
};

foo(bar);

The reason is purely because, outside of this MCVE, I'm actually using a massive object with dozens of keys, and I want to pass certain values from that across into the next part of the promise chain. I can of course use { a: args.a, b: args.b }, but I'm trying to find the shortest, cleanest way of doing this. I guess what I'm really asking for is PHP's extract()-like syntax but in ES6 JS.

Is this possible?

^{Ps, I'm aware that this could be seen as a very bad idea if the content of the object is untrusted.}

^{Pps. The environment I'm testing this on is Node 7.9.0}

Answer 1

If you want to do something with the keys but don't want to define them, why not use Object.keys or Object.entries?

const foo = (args) => {
  Object.entries(args).forEach(([key, value]) => {
    console.log(key, value);
  });
};

foo(bar);