30-seconds-of-code/snippets/forOwnRight.md

title, tags, expertise, cover, firstSeen, lastUpdated

title	tags	expertise	cover	firstSeen	lastUpdated
Iterate over object's own properties in reverse	object	intermediate	blog_images/sea-view.jpg	2018-01-18T16:45:56+02:00	2020-10-19T22:49:51+03:00

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

• Use Object.keys() 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) =>
  Object.keys(obj)
    .reverse()
    .forEach(key => fn(obj[key], key, obj));

forOwnRight({ foo: 'bar', a: 1 }, v => console.log(v)); // 1, 'bar'