How to count the number of properties in a JavaScript object
New Course Coming Soon:
Get Really Good at Git
Find out how to calculate how many properties has a JavaScript object
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.
→ Get my JavaScript Beginner's Handbook
→ Read my
JavaScript Tutorials
on The Valley of Code
→ Read my
TypeScript Tutorial
on The Valley of Code
Here is how can I help you:
- COURSES where I teach everything I know
- CODING BOOTCAMP cohort course - next edition in 2025
- BOOKS 16 coding ebooks you can download for free on JS Python C PHP and lots more
- Follow me on X