20.
Which of the following methods can be used to add or modify properties of an object in JavaScript?
Object.assign()
Object.defineProperty()
Object.create()
Object.keys()
Correct: A, B
Object.assign() can be used to shallow copy properties from one or more source objects to a target object, while Object.defineProperty() allows you to add new properties or modify existing properties with custom configuration options such as defining getters and setters.