Object.isSealed

Returns true if existing property attributes cannot be modified in an object and new properties cannot be added to the object.

Syntax

isSealed(object)

Parameters

• object

  An object.

Return value

true if the object is sealed, otherwise false.

Examples

let obj = {}
Object.seal(obj)
Object.isSealed(obj)

true

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

true