javascript mcq(multiple choice) question with answers

1. Which of the keyword is used to define the variable in the javascript?

var

let

Both A & B

None of the above

2. which of the method is used to get HTML element in javascript?

getElementbyId()

getElementsByClassName()

Both A & B

None of the above

3. What does NaN means?

Negative Number

Not a Number

Both A & B

None of the Above

4. How do we put Javascript inside HTML?

<js>

5. What will be the output?

function myfunc() {
  console.log(name);
  console.log(age);
  var name = 'BBBootstrap';
  let age = 21;
}
myfunc();

undefined and ReferenceError

BBBootstrap and undefined

ReferenceError and 21

BBBootstrap and ReferenceError

6. What's the output of the following code?

for (var i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 1);
}

1 1 1

3 2 1

3 3 3

1 2 3

7. Which one is true?

const bird = {
    size: 'small',
};

const mouse = {
    name: 'Mickey',
    small: true,
};

mouse[bird["size"]] is not valid

mouse.bird.size is not valid

mouse[bird.size] is not valid

All of them are valid

8. Which of the following is not a javascript framework?

Vue

React

Node

Laravel

9. Which of the following tag used to write javascript code?

<js>

<java>

10. What will be the output?

var x;
console.log(x); 
x = 25;

undefined

25

NaN

reference Error

11. What will be the output?

function output() {
    x = 33;
    console.log(x);
    var x;
}
output();

undefined

33

NaN

Reference Error

12. The "let" and " var" are known as:

Prototypes

Declaration statements

Data Types

Keywords

13. What will be the output?

var x = 2;
var y = "2";
console.log(x==y);

true

false

undefined

Noe of the Above

14. What will be the output?

var x = 2;
var y = "2";
console.log(x===y);

true

false

undefined

None of the above

15. What will be the output?

var x = 5;
var y = "5";
console.log(x + y);

10

55

undefined

None of the above

16. Which one is not a comparison operator?

=

<

>

!=

17. Which type of JavaScript language is?

Object oriented

Object based

Functional

None of above

18. Which symbol is used separate JavaScript statements?

Comma(,)

Colon(:)

Hyphen(_)

Semicolon(;)

19. Which event is related to the keyboard?

onfocus

onclick

onkeydown

onkeypress

20. Which on is not a mouse event?

onmouseover

onmousemove

onclick

onmousescroller

javascript mcq(multiple choice) question with answers

javascript MCQ (Multiple Choice Question) with answers

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