class method Object.keys
Object.keys(object) → Array
-
object
(Object
) – The object to pull keys from.
Returns an array of the object's property names.
Note that the order of the resulting array is browser-dependent — it
relies on the for...in
loop, for which the ECMAScript spec does not
prescribe an enumeration order. Sort the resulting array if you wish to
normalize the order of the object keys.
Object.keys
acts as an ECMAScript 5 polyfill.
It is only defined if not already present in the user's browser, and it
is meant to behave like the native version as much as possible. Consult
the ES5 specification for more
information.
Examples
Object.keys();
// -> []
Object.keys({ name: 'Prototype', version: '1.6.1' }).sort();
// -> ['name', 'version']