Iterates over all own properties of an object in reverse, running a callback for each one.

  • Use Object.keys(obj) to get all the properties of the object, Array.prototype.reverse() to reverse their order.
  • Use Array.prototype.forEach() to run the provided function for each key-value pair.
  • The callback receives three arguments - the value, the key and the object.
const forOwnRight = (obj, fn) =>
    .forEach(key => fn(obj[key], key, obj));
forOwnRight({ foo: 'bar', a: 1 }, v => console.log(v)); // 1, 'bar'