Classes And Modules(Computer Science > Javascript ) Questions and answers for exam Preparation

Question 1. The behaviour of the instances present of a class inside a method is defined by

Method
Classes
Interfaces
Classes and Interfaces

Explanation:-

Answer: Option B. -> Classes

Question 2. Consider the following code snippet :
var o = new F();
o.constructor === F
The output would be :

false
true
0
1

Explanation:-

Answer: Option B. -> true

Question 3. The keyword or the property that you use to refer to an object through which they were invoked is

from
to
this
object

Explanation:-

Answer: Option C. -> this

Question 4. The meaning for Augmenting classes is that

objects inherit prototype properties even in dynamic state
objects inherit prototype properties only in dynamic state
objects inherit prototype properties in static state
None of the mentioned

Explanation:-

Answer: Option A. -> objects inherit prototype properties even in dynamic state

Question 5. The basic difference between JavaScript and Java is

There is no difference
Functions are considered as fields
Variables are specific
Functions are values, and there is no hard distinction between methods and fields

Explanation:-

Answer: Option D. -> Functions are values, and there is no hard distinction between methods and fields

Question 6. The property of JSON() method is:

it can be invoked manually as object.JSON()
it will be automatically invoked by the compiler
it is invoked automatically by the JSON.stringify() method
it cannot be invoked in any form

Explanation:-

Answer: Option C. -> it is invoked automatically by the JSON.stringify() method

Question 7. If A is the superclass and B is the subclass, then subclass inherting the superclass can be represented as

B=inherit(A);
B=A.inherit();
B.prototype=inherit(A);
B.prototype=inherit(A.prototype);

Explanation:-

Answer: Option C. -> B.prototype=inherit(A);

Question 8. The snippet that filters the filtered set is

var t=new FilteredSet(s, {function(s) {return !(x instanceof Set);});
var t=new FilteredSet{function(s) {return !(x instanceof Set);});
var t=new FilteredSet(s, {function(s) {return (x instanceof Set);});
var t=new FilteredSet(s, {function(s) {return x;});

Explanation:-

Answer: Option A. -> var t=new FilteredSet(s, {function(s) {return !(x instanceof Set);});

Question 9. When a class B can extend another class A, we say that

A is the superclass and B is the subclass
B is the superclass and A is the subclass
Both A and B are the superclass
Both A and B are the subclass

Explanation:-

Answer: Option A. -> A is the superclass and B is the subclass

Question 10. The method that can be used to create new properties and also to modify the attributes of existing properties is

Object.defineProperty()
Object.defineProperties()
Both Object.defineProperty() and Object.defineProperties()
None of the mentioned

Explanation:-

Answer: Option C. -> Both Object.defineProperty() and Object.defineProperties()