The Secret Life of Objects

Question 1

Encapsulation

Answer 1

Distinguishing between internal complexity and external interface.

Question 2

What is a method?

Answer 2

Properties that hold function values.
rabbit.special = function(arg) {
//statement
}

Question 3

T or F: Almost all objects have prototypes.

Answer 3

True

Question 4

What is a prototype?

Answer 4

Another object that is used as a fallback source of properties.

Question 5

What happens when an object gets a request for a property that it does not have?

Answer 5

Its prototype will be searched for the property, then the prototype’s prototype, and so on.

Question 6

Object.create()

Answer 6

Creates an object with a specific prototype in the argument.

Question 7

Calling a function with the “new” keyword in front of it causes it to be treated as a _______.

Answer 7

Constructor

Question 8

An object created with the “new” keyword is said to be an ______ of its constructor.

Answer 8

instance

Question 9

What should you always do when naming a constructor so it can be easily distinguished from other functions?

Answer 9

Capitalize the first letter of the constructor name.

Question 10

Constructors (all functions) automatically get a property named _____.

Answer 10

prototype

Question 11

By default, prototypes created through constructors get?

Answer 11

a plain, empty object that derives from Object.prototype. Every instance created with this constructor will have this object as its prototype.

Question 12

Object’s prototype can be retrieved with?

Answer 12

Object.getPrototypeOf

Question 13

The actual prototype of a constructor is?

Answer 13

Function.prototype (since constructors are functions)

Question 14

Can instance object’s properties override it’s prototype properties?

Answer 14

Yes

Question 15

What are enumerable properties?

Answer 15

Properties that we create by simply assigning to them.

Question 16

The standard properties in Object.prototype are enumerable or non-enumerable?

Answer 16

non-enumerable.

Question 17

How can we define our non-enumerable properties?

Answer 17

Object.defineProperty() function. Allows us to control the type of property we are creating.

Question 18

What does the “hasOwnProperty()” method do?

Answer 18

Tells us whether the object itself has the property, without looking at its prototype.