Delete Properties from a JavaScript Object
We can also delete properties from objects like this:
delete ourDog.bark;
The delete operator removes a property from an object.
Syntax
delete expression
where expression should evaluate to a property reference, e.g.:
delete object.property
delete object['property']
Parameters
object The name of an object, or an expression evaluating to an object.
property The property to delete.
Return value
Throws in strict mode if the property is an own non-configurable property (returns false in non-strict). Returns true in all other cases.