Object.keys(obj) Last updated: 17. Oct 2026

Returns the names of an object's own properties. Works for object literals, JSON data from documents, and Docly objects such as request. Object.values() returns the values in the same order.

See also: Object.entries

Parameters

Name Type Description
obj object

The object to read property names from.

Returns

An array of property names. For an array or a text, the indexes. For null or undefined, null (standard JavaScript throws a TypeError).

Example

Code example (JS)

JS is normal JavaScript either running in the browser or on the Docly™ server.
const person = { name: "Kari", age: 42, city: "Oslo" };
write(JSON.stringify(Object.keys(person)));
/* Expected output: ["name","age","city"] */

write("\n");
write(Object.keys(person).length);   // 3

Output

The JS code above produces the output shown below:
["name","age","city"]
3