Tough Moodle Test - 76+ MCQs: Moodle test: Challenge Your Knowledge with a Comprehensive JavaScript Exam

1. What does the '!=='' operator signify in JavaScript?

Not equal value or not equal type

Equal value and equal type

Greater than or equal

Less than or equal

2. What does NaN stand for?

Not a Number

Null and None

Negative and Not

None and Not

3. Which method removes the last element from an array and returns that element?

pop()

remove()

delete()

splice()

4. What does the 'map()' method do to an array in JavaScript?

Modifies the original array

Creates a new array by transforming each element

Deletes elements from the array

Sorts the array in descending order

5. Which statement is used to skip to the next iteration in a loop?

continue

skip

jump

6. What is the result of the following code? ```javascript console.log(typeof null); ```

'object'

'null'

'undefined'

'string'

7. Which method is used to add an element to the end of an array?

append()

push()

add()

insert()

8. Which operator is used to compare two values without considering their data type?

===

!==

9. How do you call a function named 'myFunction'?

myFunction()

call myFunction()

invoke myFunction()

execute myFunction()

10. What is the result of the expression 'typeof null' in JavaScript?

'object'

'null'

'undefined'

'string'

11. Which built-in method returns the character at the specified index?

charAt()

charCodeAt()

characterAt()

indexChar()

12. In JavaScript, how do you access the last element of an array?

array[array.length - 1]

array.last()

array[-1]

array.end()

13. How do you convert a string to uppercase in JavaScript?

toUpperCase()

toUpper()

upperCase()

convertToUpper()

14. Which of the following methods removes the first element from an array?

shift()

unshift()

pop()

slice()

15. Which method is used to remove the first element from an array?

shift()

remove()

delete()

pop()

16. Which method is used to merge two or more arrays in JavaScript?

concat()

merge()

join()

combine()

17. What is the output of the following code? ```javascript console.log(typeof NaN); ```

'number'

'NaN'

'undefined'

'string'

18. What does the 'let' keyword do in JavaScript?

Declares a block-scoped variable

Declares a global variable

Declares a function-scoped variable

None of the above

19. What does the 'bind()' method do in JavaScript?

Binds an event to an element

Binds the value of 'this' to a specific object

Binds elements together in an array

Binds methods to a class

20. Which of the following is not a valid JavaScript variable name?

_variable

2variable

$variable

variableName

21. Which JavaScript method is used to remove the last element from an array?

pop()

shift()

slice()

push()

22. Which method is used to join two or more arrays?

concat()

merge()

join()

combine()

23. How can you deep clone an object in JavaScript?

Using the JSON methods

Using the Object.assign() method

Using loops

All of the above

24. What is the result of the following code? ```javascript console.log('Hello'.length); ```

25. Which event fires when the browser window is resized?

resize

windowResize

windowResized

onResize

26. How can you check if a variable is undefined in JavaScript?

Using the typeof operator

Using the undefined keyword

Checking for null

Using the .hasOwnProperty() method

27. Which symbol is used for comments in JavaScript?

28. Which function is used to display a message in a dialog box?

alert()

confirm()

prompt()

messageBox()

29. In JavaScript, how do you check if an object has a specific property?

object.hasOwnProperty('property')

object.contains('property')

object.exists('property')

object.check('property')

30. What is the result of the following code? ```javascript console.log(3 + '2' - 1); ```

31. What is the result of the expression '5' + 3 in JavaScript?

NaN

32. Which statement is used to skip the rest of the current iteration in a loop?

skip

continue

pass

33. What is the difference between '==' and '===' operators in JavaScript?

'==' checks for value equality, '===' checks for both value and type equality

'==' checks for value and type equality, '===' checks for value equality

'==' and '===' are identical in functionality

None of the above

34. In JavaScript, what does the 'finally' block do in a try-catch-finally statement?

Executes code after try and catch, regardless of the outcome

Executes code before try and catch

Executes code only if an error occurs

Executes code only if no error occurs

35. Which built-in method returns the index within the calling String object of the first occurrence of the specified value?

indexOf()

search()

locate()

find()

36. In JavaScript, how do you initiate a loop that will continue while a condition is true?

for loop

while loop

do-while loop

if statement

37. Which method is used to select elements by their CSS class in JavaScript?

getElementByClass()

selectByClass()

querySelector()

getElementsByClassName()

38. What is the result of the following code? ```javascript console.log(3 + 2 + '7');```

'57'

'12'

'327'

'57undefined'

39. What is the purpose of the 'this' keyword in JavaScript?

To refer to the current function

To refer to the global object

To refer to the parent function

To refer to the current object

40. What is the purpose of the 'Symbol' data type introduced in ES6?

To create unique identifiers

To store complex data structures

To represent strings

To handle mathematical operations

41. How do you define a function in JavaScript?

function myFunction() {}

def myFunction() {}

function = myFunction() {}

create myFunction() {}

42. What does the 'async' keyword do in a function declaration?

Makes the function asynchronous

Throws an error

Pauses the function execution

None of the above

43. Which built-in method returns the characters in a string beginning at the specified location?

substr()

slice()

getSubstring()

extract()

44. How can you implement a private variable in JavaScript?

Using closures

Using the 'private' keyword

Declaring inside a class

Using the 'privateVar' method

45. What is the output of the following code? ```javascript console.log(1 + '2' + '2');```

122

Error

46. How can you determine if a number is an integer in JavaScript?

Using the typeof operator

Using the Number.isInteger() method

Checking for decimal places

Using the Math.round() method

47. Which statement is used to throw a user-defined exception in JavaScript?

throw new Error()

exception.throw()

raise new Exception()

error.throw()

48. What does the 'typeof' operator return for a null value?

'null'

'object'

'undefined'

'string'

49. How do you check if a variable is an array in JavaScript?

isArray()

typeof()

checkArray()

arrayCheck()

50. What is the primary function of the 'typeof' operator in JavaScript?

To check if a variable is defined

To return the data type of a variable

To convert a string to a number

To concatenate two strings

Moodle JavaScript MCQ Test 1