Basics

Question 1

List all 8 datatypes in javascript

Answer 1

Number, String, Object, null, undefined, boolean, bigint, symbol

Question 2

largest value of number data type in javascript(both +ve and -ve)

Answer 2

2^53 - 1 — about 9 quadrillion

-(2^53 - 1)

Question 3

special values in number datatype

Answer 3

Nan, Infinity, -Infinity

Question 4

is there a % operation in javascript?

Answer 4

yes

Question 5

this primitive data type does not exist in javascript

Answer 5

character

Question 6

typeof(null) = ?

why does this happen?

Answer 6

object

null is not of object type, it is just what typeof returns when its operator is null

Question 7

what is the functionality of having a modal on the webpage?

Answer 7

to stop all interactions(clicks, textareas, etc) till user has interacted with modal.

Question 8

Number(“a string that can’t be converted to a number”)

Answer 8

NaN

Question 9

These are the methods used to perform String, Number, and Boolean conversions

Answer 9

String(), Number(), Boolean()

Question 10

Boolean(“0”) = ?

Answer 10

true

It is a non-empty string.

Question 11

These values on Boolean conversion become false.

Answer 11

NaN, “”, null, undefined, 0

Question 12

This is the only arithmetic operator that converts number operands to string operands,

Answer 12

+

All others convert strings to numbers.

Question 13

This operator does the same thing as Number() conversion method

Answer 13

unary + method.

Question 14

the alert function returns value of this type

Answer 14

undefined

Question 15

switch case uses strict comparison ===. True/False ?

Answer 15

True

Question 16

a function without return statement returns this value

Answer 16

undefined