JavaScript Datatype Quiz

September 16, 2025 by askitout moderator

Results

#1. How many data types are there in JavaScript?

#2. Which of the following is NOT a primitive data type in JavaScript?

String

Number

Boolean

Array

#3. What does the typeof operator return for null?

null

undefined

object

boolean

#4. How do you create a BigInt in JavaScript?

BigInt(123)

123n

Both A and B

new BigInt(123)

#5. What is the main purpose of Symbol data type?

Store large numbers

Create unique identifiers

Handle text data

Perform mathematical operations

#6. Which value is considered falsy in JavaScript?

“false”

[]

#7. What is the difference between undefined and null?

undefined is assigned automatically, null is assigned intentionally

null is assigned automatically, undefined is assigned intentionally

There is no difference

undefined is for numbers, null is for strings

#8. Which of these can be used to create a string in JavaScript?

Single quotes (‘)

Double quotes (“)

Template literals (`)

All of the above

#9. What does NaN stand for in JavaScript?

Not a Number

New Array Node

Null and None

No Assigned Name

#10. Which data type can store a collection of key-value pairs?