The basic difference between JavaScript and Java is

Functions are considered as fields

Functions are values, and there is no hard distinction between methods and fields

What is the purpose of the event window.onpopstate?

When a state object is replaced

What is the purpose of the method forward()?

Loads any random URL in the history list

Loads the previous URL in the history list

Loads a specific URL from the history list

Loads the next URL in the history list

What does the value 2 of the WebSocket attribute Socket.readyState indicate?

Established connection and communication is possible

What is the purpose of the userAgent property?

Both Identifying the data and client

What is the purpose of the area element?

Shape and coordinates of the hotspot

Which is the element that follows the use of “img”?

any element can follow the use of “img”

Why do we need to create locally scoped variables to hold value?

To optimize the testing process

To cache the reference document.location

The property of a primary expression is

basic expressions containing all necessary functions

contains variable references alone

Assume that we have to convert “false” that is a non-string to string. The command that we use is (without invoking the “new” operator)

Both false.toString() and String(false)

The statement a===b refers to

Both a and b are equal in value, type and reference address

Both a and b are equal in value

Both a and b are equal in value and type

The escape sequence ‘f’ stands for

Representation of functions that returns a value

The generalised syntax for a real number representation is

[digits][+digits][(E|e)[(+|-)]digits]

[digits][.digits][(E|e)[(+|-)]digits]

[digits][+digits][(E|e)[(+|-)]digits]

[.digits][digits][(E|e)[(+|-)]digits]

The main purpose of a “Live Wire” in NetScape is to

Support only non relational database

Create linkage between client side and server side

Permit server side, JavaScript code, to connect to RDBMS

Support only non relational database

What is the difference between the two lines given below ? !!(obj1 && obj2); (obj1 && obj2);

Both the lines result in a boolean value “True”

Both the lines result in a boolean value “False”

Both the lines checks just for the existence of the object alone

The first line results in a real boolean value whereas the second line merely checks for the existence of the objects

The primary purpose of the array map() function is that it

maps the elements of another array into itself

passes each element of the array and returns the necessary mapped elements

passes each element of the array on which it is invoked to the function you specify, and returns an array containing the values returned by that function

What will happen if reverse() and join() methods are used simultaneously ?

Reverses and concatenates the elements of the array

Reverses and stores in the same array

Reverses and concatenates the elements of the array

Which of the following is the correct code for invoking a function without this keyword at all, and also too determine whether the strict mode is in effect?

var strict = (function { return this; });

mode strict = (function() { return !this; }());

var strict = (function() { return !this; }());

302 + Mcqs in Basic And Variables in Javascript Page 4 McqOptions

151.	The basic difference between JavaScript and Java is
A.	There is no difference
B.	Functions are considered as fields
C.	Variables are specific
D.	Functions are values, and there is no hard distinction between methods and fields
Answer» E.

Discussion

152.	Consider the following code snippet : var o = new F(); o.constructor === F The output would be :
A.	false
B.	true
C.	0
D.	1
Answer» C. 0

Discussion

153.	What is the purpose of the event window.onpopstate?
A.	When a state object is replaced
B.	When a state object is added
C.	When a state object is removed
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

154.	How many parameters does the replaceState() method take?
A.	2
B.	3
C.	4
D.	5
Answer» C. 4

Discussion

155.	What is the purpose of the method forward()?
A.	Loads any random URL in the history list
B.	Loads the previous URL in the history list
C.	Loads a specific URL from the history list
D.	Loads the next URL in the history list
Answer» E.

Discussion

156.	What does an History object contain?v
A.	URL
B.	Parameters
C.	Attribute values
D.	Property
Answer» B. Parameters

Discussion

157.	Which of the following is not a WebSocket event?
A.	open
B.	close
C.	error
D.	deny
Answer» E.

Discussion

158.	How will you transmit data using the connection?
A.	send(data)
B.	Socket.send(“data”)
C.	Socket.send(data)
D.	Socket(data)
Answer» D. Socket(data)

Discussion

159.	What does the value 2 of the WebSocket attribute Socket.readyState indicate?
A.	Closed connection
B.	Handshake connection
C.	Unestablished connection
D.	Established connection and communication is possible
Answer» C. Unestablished connection

Discussion

160.	What is the purpose of the userAgent property?
A.	Identifying the data
B.	Identifying the client
C.	Both Identifying the data and client
D.	None of the mentioned
Answer» C. Both Identifying the data and client

Discussion

161.	Which of the following is not a navigator method?
A.	postEnabled
B.	reference
C.	preference
D.	all of the mentioned
Answer» D. all of the mentioned

Discussion

162.	What is the purpose of the area element?
A.	Area of the text
B.	Shape and coordinates of the hotspot
C.	Shape and area of the hotspot
D.	None of the mentioned
Answer» C. Shape and area of the hotspot

Discussion

163.	Which is the element that follows the use of “img”?
A.	area
B.	usemap
C.	map
D.	any element can follow the use of “img”
Answer» D. any element can follow the use of “img”

Discussion

164.	Which event handler is triggered when the user’s mouse moves away from a link?
A.	onMouseOver
B.	onMouseOut
C.	onMouse
D.	onMouseOnto
Answer» C. onMouse

Discussion

165.	Which event handler is triggered when the user’s mouse moves onto a link?
A.	onMouseOver
B.	onMouseOut
C.	onMouse
D.	onMouseOnto
Answer» B. onMouseOut

Discussion

166.	During the traversing of the stack when you create a locally scoped variable, where does it go after it goes to the location?
A.	Window
B.	Function
C.	Document
D.	None of the mentioned
Answer» E.

Discussion

167.	What is the function used to stop capturing the ad hoc timing ?
A.	stopadhoc()
B.	stopTimer()
C.	stopTimeLogging()
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

168.	During the traversing of the stack when you create a locally scoped variable, where does it go after it goes to the namespace?
A.	Window
B.	Function
C.	Document
D.	Location
Answer» C. Document

Discussion

169.	During the traversing through the stack, where does it go after it goes to the window?
A.	Namespace
B.	Function
C.	Document
D.	None of the mentioned
Answer» E.

Discussion

170.	What is the next step after calling the startTimeLogging()?
A.	Interpret the code
B.	Compile the code
C.	Run the code
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

171.	Why do we need to create locally scoped variables to hold value?
A.	To optimize the testing process
B.	To increase the speed
C.	To minimize memory usage
D.	To cache the reference document.location
Answer» E.

Discussion

172.	What will happen if you reference document.location from within an object?
A.	Traverses the queue
B.	Finds the bugs
C.	Traverses the stack
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

173.	The JavaScript’s syntax calling ( or executing ) a function or method is called
A.	Primary expression
B.	Functional expression
C.	Invocation expression
D.	Property Access Expression
Answer» D. Property Access Expression

Discussion

174.	The property of a primary expression is
A.	stand-alone expressions
B.	basic expressions containing all necessary functions
C.	contains variable references alone
D.	complex expressions
Answer» B. basic expressions containing all necessary functions

Discussion

175.	Consider the following snippet code var string1 = ”123”; var intvalue = 123; alert( string1 + intvalue ); The result would be
A.	123246
B.	246
C.	123123
D.	Exception
Answer» D. Exception

Discussion

176.	Assume that we have to convert “false” that is a non-string to string. The command that we use is (without invoking the “new” operator)
A.	false.toString()
B.	String(false)
C.	String newvariable=”false”
D.	Both false.toString() and String(false)
Answer» E.

Discussion

177.	The statement a===b refers to
A.	Both a and b are equal in value, type and reference address
B.	Both a and b are equal in value
C.	Both a and b are equal in value and type
D.	There is no such statement
Answer» D. There is no such statement

Discussion

178.	The snippet that has to be used to check if “a” is not equal to “null” is
A.	if(a!=null)
B.	if (!a)
C.	if(a!null)
D.	if(a!==null)
Answer» E.

Discussion

179.	The escape sequence ‘f’ stands for
A.	Floating numbers
B.	Representation of functions that returns a value
C.	f is not present in JavaScript
D.	Form feed
Answer» E.

Discussion

180.	The generalised syntax for a real number representation is
A.	[digits][.digits][(E\|e)[(+\|-)]digits]
B.	[digits][+digits][(E\|e)[(+\|-)]digits]
C.	[digits][(E\|e)[(+\|-)]digits]
D.	[.digits][digits][(E\|e)[(+\|-)]digits]
Answer» B. [digits][+digits][(E\|e)[(+\|-)]digits]

Discussion

181.	Which of the following Attribute is used to include External JS code inside your HTML Document
A.	src
B.	ext
C.	script
D.	link
Answer» B. ext

Discussion

182.	The main purpose of a “Live Wire” in NetScape is to
A.	Create linkage between client side and server side
B.	Permit server side, JavaScript code, to connect to RDBMS
C.	Support only non relational database
D.	To interpret JavaScript code
Answer» C. Support only non relational database

Discussion

183.	Consider the following code snippet : function constfuncs() { var funcs = []; for(var i = 0; i < 10; i++) funcs[i] = function() { return i; }; return funcs; } var funcs = constfuncs(); funcs[5]() What does the last statement return ?
A.	9
B.	0
C.	10
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

184.	Consider the following code snippet : var c = counter(), d = counter(); c.count() d.count() c.reset() c.count() d.count() The state stored in d is :
A.	1
B.	0
C.	Null
D.	Undefined
Answer» B. 0

Discussion

185.	What is the difference between the two lines given below ? !!(obj1 && obj2); (obj1 && obj2);
A.	Both the lines result in a boolean value “True”
B.	Both the lines result in a boolean value “False”
C.	Both the lines checks just for the existence of the object alone
D.	The first line results in a real boolean value whereas the second line merely checks for the existence of the objects
Answer» E.

Discussion

186.	For the below mentioned code snippet: var o = new Object(); The equivalent statement is:
A.	var o = Object();
B.	var o;
C.	var o= new Object;
D.	Object o=new Object();
Answer» D. Object o=new Object();

Discussion

187.	If you have a function f and an object o, you can define a method named m of o with
A.	o.m=m.f;
B.	o.m=f;
C.	o=f.m;
D.	o=f;
Answer» B. o.m=f;

Discussion

188.	Consider the following code snippet : var string2Num=parseInt("123xyz"); The result for the above code snippet would be :
A.	123
B.	123xyz
C.	Exception
D.
Answer» C. Exception

Discussion

189.	Consider the following code snippet : var tensquared = (function(x) {return x*x;}(10)); Will the above code work ?
A.	Yes, perfectly
B.	Error
C.	Exception will be thrown
D.	Memory leak
Answer» B. Error

Discussion

190.	Consider the following code snippet : var grand_Total=eval("10*10+5"); The output for the above statement would be :
A.	10*10+5
B.	105 as a string
C.	105 as an integer value
D.	Exception is thrown
Answer» D. Exception is thrown

Discussion

191.	The method or operator used to identify the array is
A.	isarrayType()
B.
C.
D.	typeof
Answer» E.

Discussion

192.	The reduce and reduceRight methods follow a common operation called
A.	filter and fold
B.	inject and fold
C.	finger and fold
D.	fold
Answer» C. finger and fold

Discussion

193.	The primary purpose of the array map() function is that it
A.	maps the elements of another array into itself
B.	passes each element of the array and returns the necessary mapped elements
C.	passes each element of the array on which it is invoked to the function you specify, and returns an array containing the values returned by that function
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

194.	Consider the following code snippet : var a = []; a.unshift(1); a.unshift(22); a.shift(); a.unshift(3,[4,5]); a.shift(); a.shift(); a.shift(); The final output for the shift() is
A.	1
B.	[4,5].
C.	[3,4,5].
D.	Exception is thrown
Answer» B. [4,5].

Discussion

195.	Consider the following code snippet : var a = [1,2,3,4,5]; a.slice(0,3); What is the possible output for the above code snippet ?
A.	Returns [1,2,3].
B.	Returns [4,5].
C.	Returns [1,2,3,4].
D.	Returns [1,2,3,4,5].
Answer» B. Returns [4,5].

Discussion

196.	What will happen if reverse() and join() methods are used simultaneously ?
A.	Reverses and stores in the same array
B.	Reverses and concatenates the elements of the array
C.	Reverses
D.	All of the mentioned
Answer» B. Reverses and concatenates the elements of the array

Discussion

197.	Consider the following code snippet o.m(x,y); Which is an equivalent code for the above code snippet?
A.	o.m(x) && o.m(y);
B.	o["m"](x,y);
C.	o(m)["x","y"];
D.	o.m(x && y);
Answer» C. o(m)["x","y"];

Discussion

198.	Which is an equivalent code to invoke a function m of class o that expects two arguments x and y?
A.	o(x,y);
B.	o.m(x) && o.m(y);
C.	m(x,y);
D.	o.m(x,y);
Answer» E.

Discussion

199.	Which of the following is the correct code for invoking a function without this keyword at all, and also too determine whether the strict mode is in effect?
A.	var strict = (function { return this; });
B.	mode strict = (function() { return !this; }());
C.	var strict = (function() { return !this; }());
D.	mode strict = (function { });
Answer» D. mode strict = (function { });

Discussion

200.	Consider the following code snippet function hypotenuse(a, b) { function square(x) { return x*x; } return Math.sqrt(square(a) + square(b)); } What does the above code result?
A.	Sum of square of a and b
B.	Square of sum of a and b
C.	Sum of a and b square
D.	None of the mentioned
Answer» B. Square of sum of a and b

Discussion

Explore topic-wise MCQs in Javascript.

The basic difference between JavaScript and Java is

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

What is the purpose of the event window.onpopstate?

How many parameters does the replaceState() method take?

What is the purpose of the method forward()?

What does an History object contain?v

Which of the following is not a WebSocket event?

How will you transmit data using the connection?

What does the value 2 of the WebSocket attribute Socket.readyState indicate?

What is the purpose of the userAgent property?

Which of the following is not a navigator method?

What is the purpose of the area element?

Which is the element that follows the use of “img”?

Which event handler is triggered when the user’s mouse moves away from a link?

Which event handler is triggered when the user’s mouse moves onto a link?

During the traversing of the stack when you create a locally scoped variable, where does it go after it goes to the location?

What is the function used to stop capturing the ad hoc timing ?

During the traversing of the stack when you create a locally scoped variable, where does it go after it goes to the namespace?

During the traversing through the stack, where does it go after it goes to the window?

What is the next step after calling the startTimeLogging()?

Why do we need to create locally scoped variables to hold value?

What will happen if you reference document.location from within an object?

The JavaScript’s syntax calling ( or executing ) a function or method is called

The property of a primary expression is

Consider the following snippet code var string1 = ”123”; var intvalue = 123; alert( string1 + intvalue ); The result would be

Assume that we have to convert “false” that is a non-string to string. The command that we use is (without invoking the “new” operator)

The statement a===b refers to

The snippet that has to be used to check if “a” is not equal to “null” is

The escape sequence ‘f’ stands for

The generalised syntax for a real number representation is

Which of the following Attribute is used to include External JS code inside your HTML Document

The main purpose of a “Live Wire” in NetScape is to

Consider the following code snippet : function constfuncs() { var funcs = []; for(var i = 0; i < 10; i++) funcs[i] = function() { return i; }; return funcs; } var funcs = constfuncs(); funcs[5]() What does the last statement return ?

Consider the following code snippet : var c = counter(), d = counter(); c.count() d.count() c.reset() c.count() d.count() The state stored in d is :

What is the difference between the two lines given below ? !!(obj1 && obj2); (obj1 && obj2);

For the below mentioned code snippet: var o = new Object(); The equivalent statement is:

If you have a function f and an object o, you can define a method named m of o with

Consider the following code snippet : var string2Num=parseInt("123xyz"); The result for the above code snippet would be :

Consider the following code snippet : var tensquared = (function(x) {return x*x;}(10)); Will the above code work ?

Consider the following code snippet : var grand_Total=eval("10*10+5"); The output for the above statement would be :

The method or operator used to identify the array is

The reduce and reduceRight methods follow a common operation called

The primary purpose of the array map() function is that it

Consider the following code snippet : var a = []; a.unshift(1); a.unshift(22); a.shift(); a.unshift(3,[4,5]); a.shift(); a.shift(); a.shift(); The final output for the shift() is

Consider the following code snippet : var a = [1,2,3,4,5]; a.slice(0,3); What is the possible output for the above code snippet ?

What will happen if reverse() and join() methods are used simultaneously ?

Consider the following code snippet o.m(x,y); Which is an equivalent code for the above code snippet?

Which is an equivalent code to invoke a function m of class o that expects two arguments x and y?

Which of the following is the correct code for invoking a function without this keyword at all, and also too determine whether the strict mode is in effect?

Consider the following code snippet function hypotenuse(a, b) { function square(x) { return x*x; } return Math.sqrt(square(a) + square(b)); } What does the above code result?