← flaviocopes.com

How to count the number of properties in a JavaScript object

Published Dec 07 2018

Use the Object.keys() method, passing the object you want to inspect, to get an array of all the (own) enumerable properties of the object.

Then calculate the length of that array by checking the length property:

const car = {
  color: 'Blue',
  brand: 'Ford',
  model: 'Fiesta'
}

Object.keys(car).length

I said enumerable properties. This means their internal enumerable flag is set to true, which is the default. Check MDN for more info on this subject.



Wanna go from noobie to expert?

I wrote an entire book on this topic 👇

I also got a super cool course 👇

© 2023 Flavio Copes Flavio Copes using Notion to Site Notion to Site. Follow on Twitter

Solopreneur? Wannabe? Adventure awaits