JavaScript MCQ

Soopro Pathshala provides JavaScript MCQ(Multiple Choice Questions)

1. Which of the following methods can be used to display data in Javascript?

a) confirm()

b) console.log()

c) alert()

d) all of above

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2. How can a datatype be declared to be a constant type?

a) cons

b) const

c) c

d) constant

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3. What keyword is used to check whether a given property is valid or not?

a) is

b) in

c) exists

d) default

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4. How many way to link javascript __

a) 2

b) 4

c) 3

d) 1

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5. can var, const, or let all keyword use in javascript.

a) Yes

b) No

c) only let or const

d) only var or let

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6. In javaScript this is sign of [{}]

a) object

b) array

c) object array

d) array object

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7. How to declare function in javascript.

a) using function keyword

b) using var keyword

c) using new keyword

d) using const keyword

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8. How many types of loop work in javaScript?

a) 2

b) 3

c) 4

d) 6

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9. In which year javaScript lunched?

a) 1954

b) 1994

c) 1995

d) 1987

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10. Which one is view engine of google chrome?e

a) V8

b) Spider

c) Spider monkey

d) Chrome

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11. A javaScript file save with __extension

a) .json

b) .js

c) .script

d) .ts

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12. Who is developer of JS?

a) Tim Berner Lee

b) Brendan Eich

c) James gosling

d) none of these

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13. How to define multi lines comments in JavaScript?

a) //

b) /* Hello World */

c) %Hello World%

d) #Hello World#

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14. In switch case use__?

a) Return

b) Break

c) both a and b

d) none of the above

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15. What is extension of JavaScript?

a) .js

b) .java

c) .javascript

d) none of the above

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16. in Javascript alert(),cofirm(), and prompt() are message boxes

a) yes

b) no

c) may be

d) cant say

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17. In javaScript "=== "operator defines what?

a) non inentical

b) it compare value and data type both

c) unequal

d) not equal to

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18. Among of the following is a language of javascript?

a) text/javascript

b) text/ECMAScript

c) text/VBScript

d) JavaScript/VBScript

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19. Which of the following is the property that is triggered in response to JS errors?

a) onclick

b) onerror

c) onmessage

d) onexception

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20. JavaScript is ____language

a) Application

b) Scripting

c) Programming

d) None of these

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21. Which company developed JavaScript?

a) IBM

b) Bell Labs

c) Netscape

d) Sun Microsystems

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22. JavaScript is __ Side Scripting Language.

a) ISP

b) Server

c) Client

d) None of the above

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23. Which of the following is not JavaScript Data Types?

a) Undefined

b) Number

c) Boolean

d) Float

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24. Which of the following code creates an object?

a) var book=Object();

b) var book=new Object();

c) var book=new Book();

d) var book=OBJECT();

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25. JavaScript is designed for the following purpose:

a) To style HTML pages

b) To execute Queries related to databases on a server

c) To add interactivity to html pages

d) all of the above

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26. To include external JS code inside an HTML document which attribute is used?

a) src

b) link

c) script

d) href

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27. Which function in js used to convert text to upper case?

a) toLocalUpperCase()

b) toString()

c) substring()

d) toUpperCase()

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28. Which of the following is not considered a JavaScript operator?

a) this

b) new

c) typeof

d) delete

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29. Comments in JS are ignored by___

a) Browser

b) JVM

c) Operating System

d) Compiler

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30. "+=" operator can operate on following data values.

a) all options

b) string

c) integer

d) float

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31. How many ways to call function in JavaScript?

a) call by value and call by reference

b) call by function

c) call by data value

d) call by compiler

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32. How many types of data type in javaScript.

a) 1

b) 2

c) 3

d) 4

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33. How many types of function in javaScript.

a) user define

b) user define or pre define

c) pre define

d) none of the above

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34. Which is JavaScript reserved keywords?

a) try

b) catch

c) function

d) all of above

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35. unary operator work on__?

a) single operand

b) two operands

c) two or more than two operands

d) none of above

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36. How many ways to define user defined function?

a) 1

b) 2

c) 3

d) 4

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37. When an operator’s value is NULL, the typeof returned by the unary operator is____

a) Boolean

b) Undefine

c) Object

d) Integer

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38. What is anonymous function in javaScript?

a) A function without any name

b) A special function with name

c) Data type

d) none of above

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39. getElementsByClassName() Returns____

a) can access html elements by class name

b) given name

c) given id

d) both a and b

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40. How many types of validation?

a) client side

b) server side

c) both a and b

d) none of above

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41. It was initially named ___?

a) Mocha

b) Live script

c) Type script

d) none of above

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42. Which javascript engine developed by Google for Chrome and used in Node JS?

a) V8

b) Spider Monkey

c) JavaScript Core

d) none of above

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43. Which javascript engine used in Firefox?

a) V8

b) Spider Monkey

c) JavaScript Core

d) none of above

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44. A__ is single or multiple lines, which give some information about the current program.

a) Comment

b) script

c) both a and b

d) none of above

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45. ___ are reserved words in JavaScript, which cannot be used as variable names or function names.

a) variable

b) comment

c) keyword

d) none of above

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46. ______Display a popup box with the specified message with the OK button.

a) alert(message)

b) confirm()

c) prompt()

d) none of above

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47. ______Display a popup box with the specified message with OK and Cancel buttons.

a) alert(message)

b) confirm()

c) prompt()

d) none of above

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48. ______Display a popup box to take the user's input with the OK and Cancel buttons.

a) alert(message)

b) confirm()

c) prompt(message, default value)

d) none of above

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49. ______means anything that can vary.

a) script

b) style

c) variable

d) none of above

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50. _____is used to declare variables since JavaScript was created

a) var keyword

b) let keyword

c) const keyword

d) none of above

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51. _____ removes the confusion and error of var. It is the new and recommended way of declaring variables in JavaScript.

a) var keyword

b) let keyword

c) const keyword

d) none of above

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52.______ is used to declare a constant variable that cannot be changed once assigned a value.

a) var keyword

b) let keyword

c) const keyword

d) none of above

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53.Variables declared out of any function are called ___

a) local variable

b) global variable

c) const keyword

d) none of above

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54.Variables declared inside of any function are called ___

a) local variable

b) global variable

c) const keyword

d) none of above

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55.the ___ are used to combine two or more conditions

a) logical operators

b) comparison oprators

c) assignment operators

d) none of above

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56.The ______ starts with conditional expression followed by the ? operator

a) Ternary operator

b) comparison oprator

c) assignment operator

d) none of above

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57. A ____ is a primitive data type that is used for textual data

a) string

b) var

c) let

d) none of above

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58. The ____ type is a numeric primitive type that can store integers with arbitrary precision.

a) Big int

b) int

c) let

d) none of above

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59. The ____ is a primitive data type in JavaScript.

a) boolean

b) var

c) let

d) none of above

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60. An ___ is a non-primitive, structured data type in JavaScript.

a) boolean

b) object

c) let

d) none of above

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