Object.isSealed()
The Object.isSealed() method determines if an object is
sealed.
Syntax
Object.isSealed(obj)
Parameters
obj- : The object which should be checked.
Return value
A Boolean indicating whether or not the given object is sealed.
Description
Returns true if the object is sealed, otherwise false. An
object is sealed if it is not extensible and
if all its properties are non-configurable and therefore not removable (but not
necessarily non-writable).