Explore topic-wise MCQs in Javascript.

This section includes 157 Mcqs, each offering curated multiple-choice questions to sharpen your Javascript knowledge and support exam preparation. Choose a topic below to get started.

51.

*/*_What is the function of the closure compiler??

A. Download faster
B. Run faster
C. Both Download faster and Run faster
D. None of the mentioned
Answer» D. None of the mentioned
52.

*/*_What is the necessity to have API??

A. Guide to performing activities
B. Describe particular task
C. Both performing activities and Describe particular task
D. None of the mentioned
Answer» C. Both performing activities and Describe particular task
53.

*/*_What is the reason for avoiding the attributes property in the HTML DOM??

A. Found unncessary
B. Attributes don’t have attributes
C. Attributes have attributes
D. None of the mentioned
Answer» C. Attributes have attributes
54.

*/*_What kind of path can the PHP file be??

A. Absolute
B. Relative
C. Either Absolute or Relative
D. Both Absolute and Relative
Answer» D. Both Absolute and Relative
55.

*/*_Which program code doesn’t need preprocessing before being run??

A. Text
B. Script
C. Both Text and Script
D. None of the mentioned
Answer» C. Both Text and Script
56.

*/*_In which format does JavaScript support external JavaScript??

A. .js
B. .php
C. .js/php
D. .jss
Answer» B. .php
57.

*/*_Which algorithm supports blobs??

A. Structured clone algorithm
B. Double buffer algorithm
C. Chen’s algorithm
D. Retrieval algorithm
Answer» B. Double buffer algorithm
58.

*/*_Which is the function that allows a worker to terminate itself??

A. close()
B. exit()
C. terminate()
D. halt()
Answer» B. exit()
59.

*/*_The style property belongs to while of the following object??

A. Element
B. Window
C. Location
D. None of the mentioned
Answer» B. Window
60.

*/*_A Blob URL can be created using which of the following function??

A. createURL()
B. createObjectURL()
C. designURL()
D. URLCreation()
Answer» C. designURL()
61.

*/*_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
62.

*/*_What is the property to access the first child of a node??

A. timestamp.Child1
B. timestamp.Child(1)
C. timestamp.Child(0)
D. timestamp.firstChild
Answer» E.
63.

*/*_Which of the following is not a JavaScript framework??

A. Rico
B. Prototype
C. Joco
D. DoJo
Answer» E.
64.

*/*_Which of the following has a lesser benchmark time for using JQuery to access DOM versus pure JavaScript in milliseconds??

A. Chrome JQueryDOM_
B. Chrome JSDOM_benc
C. Firefox JQueryDOM_
D. Firefox JSDOM_benc
Answer» E.
65.

*/*_What is a framework??

A. User time efficiency
B. Author time efficiency
C. Both User time and Author time efficiency
D. None of the mentioned
Answer» C. Both User time and Author time efficiency
66.

*/*_What is the procedure to view the console in the Firefox??

A. Tools->Error Console
B. Tools->Error Window
C. Help->Error Console
D. None of the mentioned
Answer» B. Tools->Error Window
67.

*/*_What is it called when we make a mistake in the script??

A. Error
B. Bug
C. Mistake
D. All of the mentioned
Answer» C. Mistake
68.

*/*_How to find the index of a particular string??

A. position()
B. index()
C. indexOf()
D. none of the mentioned
Answer» D. none of the mentioned
69.

*/*_In which part does the form validation occur??

A. Client
B. Server
C. Both Client and Server
D. None of the mentioned
Answer» C. Both Client and Server
70.

*/*_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
71.

*/*_What are the benefits of closure compiler??

A. Efficiency
B. Code checking
C. Both Efficiency and Code checking
D. None of the mentioned
Answer» E.
72.

*/*_In what way does the closure compiler help in checking the code??

A. Warnings
B. Suddenly aborts
C. Rejects malicious inputs
D. All of the mentioned
Answer» B. Suddenly aborts
73.

*/*_The object that looks to the thread that creates it is?

A. Window
B. Worker
C. Element
D. Hash
Answer» C. Element
74.

*/*_Which property is used to manage multiple event handlers??

A. onmessage
B. onerror
C. both onmessage and onerror
D. none of the mentioned
Answer» D. none of the mentioned
75.

*/*_The blobs are broken into smaller pieces using which of the following functions??

A. partition()
B. cut()
C. sliceall()
D. slice()
Answer» E.
76.

*/*_Which method facilitates in uploading a Blob to a server??

A. send()
B. pass()
C. upload()
D. store()
Answer» B. pass()
77.

*/*_When does a memory leak happen??

A. Browser doesn’t release memory from objects unnecessary
B. Browser releases too many memories
C. All of the mentioned
D. None of the mentioned
Answer» B. Browser releases too many memories
78.

_ What is the purpose of the Attr object in the HTML DOM?$?

A. Used to focus on a particular part of the HTML page
B. HTML Attribute
C. Used to arrange elements
D. None of the mentioned
Answer» C. Used to arrange elements
79.

_ What are the benefits of closure compiler?$?

A. Efficiency
B. Code checking
C. Both Efficiency and Code checking
D. None of the mentioned
Answer» E.
80.

_ 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
81.

_ The object that looks to the thread that creates it is$?

A. Window
B. Worker
C. Element
D. Hash
Answer» C. Element
82.

_ In what way does the closure compiler help in checking the code?$?

A. Warnings
B. Suddenly aborts
C. Rejects malicious inputs
D. All of the mentioned
Answer» B. Suddenly aborts
83.

_ Which of the following ensures additional interactivity mechanism?$?

A. WAI ARIA
B. Geolocation API
C. Object API
D. None of the mentioned
Answer» B. Geolocation API
84.

_ When does one use the method startOverlays()?$?

A. Edit ad request
B. Delete ad request
C. Create ad request
D. None of the mentioned
Answer» D. None of the mentioned
85.

_ Which of the following attribute takes the source of the PHP file?$?

A. img
B. src
C. source
D. none of the mentioned
Answer» C. source
86.

_ Which of the following is the method used to add an element to the desired location?$?

A. add.element()
B. element.add()
C. element.appendChild()
D. none of the mentioned
Answer» D. none of the mentioned
87.

_ Which of the following is a way to retain an object in memory?$?

A. Console Log
B. Closures
C. Destory objects
D. All of the mentioned
Answer» B. Closures
88.

_ The blobs are broken into smaller pieces using which of the following functions?$?

A. partition()
B. cut()
C. sliceall()
D. slice()
Answer» E.
89.

_ Which property is used to manage multiple event handlers?$?

A. onmessage
B. onerror
C. both onmessage and onerror
D. none of the mentioned
Answer» D. none of the mentioned
90.

_ When does a memory leak happen?$?

A. Browser doesn’t release memory from objects unnecessary
B. Browser releases too many memories
C. All of the mentioned
D. None of the mentioned
Answer» B. Browser releases too many memories
91.

_ Which method facilitates in uploading a Blob to a server?$?

A. send()
B. pass()
C. upload()
D. store()
Answer» B. pass()
92.

_ 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.
93.

_ If we have an object r and want to know if it is a Range object, we can write:$?

A. r typeof Range
B. r is Range
C. r equals Range
D. r instanceof Range
Answer» E.
94.

_ How can you find a client’s browser name?$?

A. browser.name
B. navigator.appName
C. client.navName
D. none of the mentioned
Answer» C. client.navName
95.

_ What is the purpose of the function eval?$?

A. Executes the string as an integer
B. Gets the value of the string
C. Executing string as JavaScript
D. None of the mentioned
Answer» D. None of the mentioned
96.

_ What is the purpose of a JavaScript debugger?$?

A. Correction of errors
B. Placing script execution under control
C. Correction of errors & Placing script execution under control
D. None of the mentioned
Answer» C. Correction of errors & Placing script execution under control
97.

_ Which of the following is the window that the Firefox sends the error messages to?$?

A. Bug Window
B. Error Issues
C. Error Window
D. Error Console
Answer» E.
98.

_ What is the purpose of the mimeTypes property of a plug-in entry?$?

A. Contains MIME properties
B. Contains MIME sizes
C. Contains MIME types
D. None of the mentioned
Answer» D. None of the mentioned
99.

_ Which is the function that is called to validate a data?$?

A. validate()
B. valid()
C. validation()
D. none of the mentioned
Answer» E.
100.

_ Which object is the top of the hierarchy?$?

A. Window Object
B. Document Object
C. Form Object
D. Form Control Elements
Answer» B. Document Object