51 JavaScript MCQ Questions in english

51 JavaScript MCQ Questions in english हिन्दी

51. Which of the following operators is used to determine whether or not a particular property exists?

A. Exists

B. exist

C. in

D. within

50. 25. Which of these keywords is used to check for exceptions in the block?

A. check

B. throw

C. catch

D. try

49. 24. Which of the following statements about Thread is untrue?

A. start() method is used to begin execution of the thread

B. run() method is used to begin execution of a thread before start() method in special cases

C. A thread can be formed by implementing Runnable interface only

D. A thread can be formed by a class that extends Thread class

48. Which of the following selections serves as the literal hexadecimal start?

A. 00

B. 0x

C. Both 0x and 0X

D. 0X

47. 23.Which of these packages includes the Java Stack Overflow exception?

A. java.io

B. java.system

C. java.lang

D. java.util

46. Which type of variable among the following is volatile?

A. Immutable variable

B. Dynamic variable

C. Volatile variable

D. Mutable variable

45. If the names of two variables are the same, which one is the dominant one?

A. Global variable

B. The two of the above

C. The local element

D. None of the above

44. The names of the "function" and "var" are:

A. Keywords

B. Data types

C. Declaration statements

D. Prototypes

43. What happens if an interpreter runs into an empty statement:

A. Shows a warning

B. Prompts to complete the statement

C. Throws an error

D. Ignores the statements

42. What does a block of statements mean in JavaScript?

A. Conditional block

B. block that combines a number of statements into a single compound statement

C. both conditional block and a single statement

D. block that contains a single statement

41. Which of the following doesn't constitute a JavaScript error?

A. Missing of Bracket

B. Division by zero

C. Syntax error

D. Missing of semicolons

40. Which of the following properties is the one that JS faults cause to be triggered?

A. onclick

B. onerror

C. onmessage

D. onexception

39. 22. What will the following Java programme produce?

A. www.sanfoundry.com

B. https://www.sanfoundry.com/javamcq

C. sanfoundry

D. sanfoundry.com

38. which is not a framework?

A. JavaScript .NET

B. JavaScript

C. Cocoa JS

D. jQuery

37. Why are JS event handlers necessary?

A. Allows JavaScript code to alter the behaviour of windows

B. Adds innerHTML page to the code

C. Change the server location

D. Performs handling of exceptions and occurrences

36. Which of the subsequent operations and/or procedures does JavaScript utilise in place of == and!=?

A. JavaScript uses equalto()

B. JavaScript uses equals() and notequals() instead

C. JavaScript uses bitwise checking

D. JavaScript uses === and !== instead

35. 21. Of the following, which is not a Java Profiler?

A. JProfiler

B. Eclipse Profiler

C. JVM

D. JConsole

34. Why is a JavaScript Engine necessary?

A. Both Compiling & Interpreting the JavaScript

B. Parsing the javascript

C. Interpreting the JavaScript

D. Compiling the JavaScript

33. 20. Which of the following describes the superclass of each Java class?

A. ArrayList

B. Abstract class

C. Object class

D. String

32. What fundamental differences exist between Java and JavaScript?

A. Functions are considered as fields

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

C. Variables are specific

D. There is no difference

31. 19. Which of the following keywords is used in Java to define interfaces?

A. intf

B. Intf

C. interface

D. Interface

30. What kind of scoping method does JavaScript employ?

A. Sequential

B. Segmental

C. Lexical

D. Literal

29. 18. Which of these is a Java selection statement?

A. break

B. break

C. for()

D. if()

28. Which of the following best describes what takes place when JavaScript software is created on a Unix machine?

A. will work perfectly well on a Windows Machine

B. will be displayed as JavaScript text on the browser

C. will throw errors and exceptions

D. must be restricted to a Unix Machine only

27. 17. In Java, what exception is raised when memory is exhausted?

A. MemoryError

B. OutOfMemoryError

C. MemoryOutOfBoundsException

D. MemoryFullException

26. 16. What does the term "compiled Java classes" mean?

A. .txt

B. .js

C. .class

D. .java

25. A JavaScript Code Snippet can be called using which of the following?

A. Function/Method

B. Preprocessor

C. Triggering Event

D. RMI

24. 15. What will the following Java code snippet produce?

A. The snippet compiles and runs but does not print anything

B. The snippet compiles, runs and prints 0

C. The snippet compiles, runs and prints 1

D. The snippet does not compile

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