Object.isExtensible

Returns true if new properties can be added to an object.

Syntax

isExtensible(object)

Parameters

• object

  An object.

Return value

true if new properties can be added to the object, otherwise false.

Examples

let obj = {}
Object.isExtensible(obj)

true

let obj = {}
Object.preventExtensions(obj)
Object.isExtensible(obj)

false

let obj = {}
Object.freeze(obj)
Object.isExtensible(obj)

false