JavaScript Classes and Modules Test(1st)

What is being imposed on each subset to ensure that it conforms to the subset?

1 Mark(s)

All of the mentioned
A static verifier that parses code
A parser to parse the code
A parser that parses and adds to the subset

The snippet that filters the filtered set is

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

The regular expression to match any one character not between the brackets is

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[…]
[^]
[^…]
[D]

The functions provide() and require() of Dojo toolkit and Google’s Closure library are used for

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declaring modules
none of the mentioned
loading and declaring modules
declaring and loading modules

Why does JavaScript subset disallow == and !=?

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None of the mentioned
It uses equals() and notequals() instead
It uses === and !== instead
It uses bitwise checking

Which method to use while working with XML fragments, instead of XML()?

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XMLArray()
XMLList()
XMLInterface()
XMLClass()

Consider the following code snippet

let succ = function(x) x+1, yes = function() true, no = function() false;

What convenience does the above code snippet provide?

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Shorthand expression
Functional behaviour
No convenience
Modular behaviour

What does the subexpression /java(script)?/ result in ?

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None of the mentioned
It matches “java” followed by the optional “script”
It matches “java” followed by any number of “script”
It matches “java” followed by a minimum of one “script”

Which exception does the Iterators throw from their next() method when there are no more values to iterate, that work on finite collections ?

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Abort
AbortIteration
ExitIteration
StopIteration

The scope of a function is also called as

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Private function
The function’s scope
Modulated function
Module function

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

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to
object
this
from

Consider the following statement containing regular expressions

var text = "testing: 1, 2, 3"; 
var pattern = /d+/g;

In order to check if the pattern matches, the statement is

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text==pattern
text.equals(pattern)
pattern.test(text)
text.test(pattern)

Consider the following code snippet :

var o = new F();
o.constructor === F

The output would be :

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1
0
false
true

Modules that have more than one item in their API can

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Assign itself to a global variable
Invoke another module of the same kind
Invoke another module of the same kind
Return a namespace object

You can refresh the webpage in JavaScript by using

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window.reload
window.refresh
page.refresh
location.reload

Consider the following code snippet

let x=x+1;
console.log(x);

What will be the result for the above code snippet?

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Null
NaN
ReferenceError
0

What will be the reaction when a catch clause has no conditionals ?

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Takes it to be 1
Takes it to be false
Takes it to be 0
Takes it to be true

The let keyword can be used

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to define variables that are scoped to a single expression
as a block statement, to define new variables
all of the mentioned
in a for or for/in loop, as a substitute for var

The maximum number of global symbols a module can define is

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2
3
4
1

What is the code to be used to trim whitespaces ?

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let trimmed = l.trim();
let trimmed = for(l in lines));
let trimmed = (trim(l));
let trimmed = (l.trim() for (l in lines));

What will be the result when non greedy repetition is used on the pattern /a+?b/ ?

1 Mark(s)

Matches the letter b preceded by the fewest number of a’s possible
Matches the letter b preceded by any number of a
Matches letter a preceded by letter b, in the stack order
None of the mentioned

Consider the following code snippet

[x,y]=[y,x];

What is the result of the above code snippet?

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Swap the value of the two variables
Creates a new reference object
Flashes an error
Throws exception

Which method of the iterable object returns an iterator object for the collection?

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iterator()
_iterator_()
_return_iterator_()
_iteration_()

Consider the following code snippet

console.log(p)

If p is not defined, what would be the result or type of error?

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Zero
ReferenceError
ValueNotFoundError
Null

The ‘$’ present in the RegExp object is called a

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character
metacharacter
metadata
matcher

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

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

The properties() method is a

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None of the mentioned
Enumerable method
Operational method
Non-enumerable method

The Crockford’s subset doesnot include which function in JavaScript?

1 Mark(s)

eval()
coeval()
equivalent()
equal()

The object whose properties are inherited by all instances of the class, and properties whose values are functions behaving like instance methods of the class, is

1 Mark(s)

Prototype object
Destructor object
Instance object
Constructor object

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

1 Mark(s)

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

Which of the following is an example to perform the most common XML manipulations using the XML objects invocation?

1 Mark(s)

appendChildBefore(…)
insertChildBefore()
insertChildAfter()
appendChildAfter(…)

Consider the following code snippet

var sets = com.davidflanagan.collections.sets;

What is the programmer trying to do in the above code snippet?

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Importing the entire module
Importing a namespace
Importing a module partially
Importing a single module

The properties of the objects act like different kinds of class members. They are

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Public object, Private object, Protected object
Instance method, Static object, Dynamic object
Constructor object, Function object, Destructor object
Constructor object, Prototype object, Instance object

What does /[^(]* regular expression indicate ?

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Match zero or more characters that are not open paranthesis
Match one or more characters that are open paranthesis
Match one or more characters that are not open paranthesis
Match zero or more characters that are open paranthesis

Which is the subset that is a secure container designed for the purpose of safely running untrusted JavaScript?

1 Mark(s)

None of the mentioned
Both Sandbox and Good Parts
The Good Parts
Sandbox

What can be done in order to avoid creation of global variables in JavaScript?

1 Mark(s)

To use a method that defines all the variables
To use an object as its namespace
To use an object that has the reference to all the variables
To use global functions

Which is the correct code that returns a complex number that is the complex conjugate of this one?

1 Mark(s)

Complex.prototype.conj = function() { return new Complex(this.r, -this.i); };
Complex.prototype.conj = function() { return Complex(this.r, -this.i); };
Complex.prototype.conj = function() { new Complex(this.r, -this.i); };
Complex.prototype.conj = function() { return (this.r, -this.i); };

To define each of the set classes as a property of the sets object (namespace) for the module, the statement is

1 Mark(s)

sets.SingletonSet = sets.extend(...);
sets = sets.AbstractEnumerableSet.extend();
sets = sets.extend(...);
sets.SingletonSet = sets.AbstractEnumerableSet.extend(...);

The basic difference between JavaScript and Java is

1 Mark(s)

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

Consider the following statement

var Set = sets.Set;
var s = new Set(1,2,3);

What could be the efficiency quotient of the above two statements ?

1 Mark(s)

There is no efficiency quotient, the programmer tries to make it inefficient
The programmer needs to import the Sets everytime he wants to use it
The programmer imports at once the frequently used values into the global namespace
All of the mentioned

Which of the following is the descendant operator?

1 Mark(s)

@
..
…
*

The main difference between the variables declared with var and with let is

1 Mark(s)

none of the mentioned
var is confined to a particular function but let is not
var defines values based on conditions but let does not
let is confined to a particular function but var is not

When will the finally block be called?

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When there is exception
When there is no exception
When the catch doesnot match
None of the mentioned

What is the code required to delete all “weight” tags?

1 Mark(s)

delete pt.element[all];
delete pt..weight;
delete pt;
delete weight(pt).all;

Which are usually variables that are used internally in object methods and also are globally visible variables?

1 Mark(s)

Internal properties
Variable properties
Method properties
Object properties

The method that performs the search-and-replace operation to strings for pattern matching is

1 Mark(s)

replace()
searchandreplace()
add()
edit()

The provides() function and the exportsobject are used to

1 Mark(s)

Register the module’s API and Store their API
Store the module’s API and register their API
Store the module’s API
None of the mentioned

What would be the result of the following statement in JavaScript using regular expression methods ?

1 Mark(s)

Returns [“123″,”456″,”789”]
Returns [“123″”456″”789”]
Throws an exception
Returns [1,2,3,4,5,6,7,8,9]

Why is the this keyword forbidden in JavaScript?

1 Mark(s)

Functions should not access the global objects
Highly memory consuming
Functions should access the global objects
Very inefficient to use

Which is the object that defines methods that allow complete control over page content?

1 Mark(s)

The client-side document object
The server-side document object
Both client-side and server-side document object
None of the mentioned

Consider the following code snippet

data.sort(function(a,b),b-a);

What does the above code do?

1 Mark(s)

Sort in the alphabetical order
Sort in reverse alphabetical order
Sort in the chronological order
Sort in reverse numerical order

What is the procedure to add methods to HTMLElement so that they will be inherited by the objects that represent the HTML tags in the current document?

1 Mark(s)

HTMLElement.prototype(…)
HTML.elements(add)
HTML.addmethods()
HTMLElement.prototype

The property of JSON() method is:

1 Mark(s)

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

Consider the following code snippet

function oddsums(n) 
{
     let total = 0, result=[]; 
     for(let x = 1; x <= n; x++) 
     { 
        let odd = 2*x-1; 
        total += odd;
        result.push(total);
     }
     return result;
}

What would be the output if

oddsums(5);

is executed afted the above code snippet ?

1 Mark(s)

Returns [3,6,9,12,15]
Returns [1,2,3,4,5]
Returns [1,3,5,7,9]
Returns [1,4,9,16,25]

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

1 Mark(s)

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

What is the most essential purpose of parantheses in regular expressions ?

1 Mark(s)

Define pattern matching techniques
All of the mentioned
Define subpatterns within the complete pattern
Define portion of strings in the regular expression

Which was one of the first security subsets proposed?

1 Mark(s)

dojox.secure
ADSafe
Caja
FBJS

Which looping statement allows XML tags to appear in JavaScript programs and adds API for operating on XML data?

1 Mark(s)

for loop
for/each loop
while loop
all of the mentioned

How can we make methods available on all objects?

1 Mark(s)

Object.methods(add)
Object.add.methods(…)
Object.add(methods)
Object.prototype

The meaning for Augmenting classes is that

1 Mark(s)

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

The class that represents the regular expressions is

1 Mark(s)

RegExp
StringExp
RegExpClass
RegExpObj

Which is the subset that transforms web content into secure modules that can be safely hosted on a web page?

1 Mark(s)

Microsoft Web Sandbox
dojox.secure
Caja
ADsafe

Why was “The Good Parts” designed as a language subset in JavaScript?

1 Mark(s)

To improve programmer productivity
To create an in-built compiler and interpreter
To balance the work load of the programmer
To improve programmer flexibility

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

1 Mark(s)

Method
Classes
Interfaces
Classes and Interfaces

Which are the two functions that are not allowed in any secure subset?

1 Mark(s)

debugger() and test()
evaluate() and restrict()
eval() and the Function() constructor
eval() and debugger()

What is the return type of typeof for standard JavaScript objects?

1 Mark(s)

xml
html
object
dom

The four kinds of class members are

1 Mark(s)

Global methods, Local methods, Dynamic methods, Static methods
Instance fields, Instance methods, Class fields, Class methods
Instance fields, Non-instance fields, Dynamic methods, Global methods
Instance methods, Instance fields, Static method, Dynamic method

Consider the following code snippet

const pi=3.14;
var pi=4;
console.log(pi);

What will be the output for the above code snippet?

1 Mark(s)

Prints 4
Prints 3.14
This will flash an error
Ambiguity

JavaScript Classes and Modules Test(1st) : Question 1 of 68