JSON Quiz Test Online (30 random Questions) 2026

This quick 30-minute challenge consists of 30 random multiple-choice questions designed to test your knowledge across various JSON topics, including the introduction to JSON, JSON syntax and basics, data types, operations in JavaScript, APIs and JSON, advanced structures, JSON Schema, tools and debugging, as well as performance and security considerations. Whether you’re new to JSON or looking to refine your skills, this quiz will enhance your understanding of JSON’s role in modern web development.

0 votes, 0 avg

You have 30 minutes to complete the quiz. The timer will start when you click the 'Start Quiz' button. Please ensure you are ready before beginning.

Time is up! Your quiz has ended. Your responses have been submitted automatically.

30 Minutes JSON Quiz Test Online

Welcome to the JSON Quiz! This quick 30-minute challenge consists of 30 random multiple-choice questions designed to test your knowledge across various JSON topics, including the introduction to JSON, JSON syntax and basics, data types, operations in JavaScript, APIs and JSON, advanced structures, JSON Schema, tools and debugging, as well as performance and security considerations. Whether you're new to JSON or looking to refine your skills, this quiz will enhance your understanding of JSON's role in modern web development.

1 / 30

1. How can you validate JSON in a secure and efficient way?

A) Ignore validation for trusted sources

B) Use custom regular expressions

C) Manually check the JSON

D) Use a JSON Schema validator

2 / 30

2. How is JSON used in data interchange for machine learning models?

A) To render visualizations

B) To train models directly

C) To serialize model configurations and results

D) To compile machine learning libraries

3 / 30

3. Which character is used to enclose a JSON array?

A) ()

B) []

C) <>

D) {}

4 / 30

4. In which cloud service is JSON commonly used for defining infrastructure as code?

A) Firebase

B) Microsoft Azure

C) Amazon Web Services (AWS) CloudFormation

D) DigitalOcean

5 / 30

5. How do you validate that a JSON object has no additional fields?

A) properties: []

B) additionalFields: false

C) maxProperties: 0

D) additionalProperties: false

6 / 30

6. How can JSON responses be protected from being cached by unauthorized users?

A) Use the Cache-Control header with no-store

B) Minify the JSON data

C) Use large nested objects

D) Convert JSON to XML

7 / 30

7. Why is it important to validate JSON data received from external sources?

A) To improve parsing speed

B) To prevent unexpected errors and security vulnerabilities

C) To compress JSON

D) To convert JSON into JavaScript objects

8 / 30

8. What is the default HTTP method for the fetch() function?

A) GET

B) POST

C) PUT

D) PATCH

9 / 30

9. What is the output of JSON.stringify([1, undefined, 2])?

A) "[1, undefined, 2]"

B) "[1, , 2]"

C) Throws a TypeError

D) "[1, null, 2]"

10 / 30

10. What does a 404 status code signify in an API response?

A) Unauthorized access

B) Bad request

C) Internal server error

D) Resource not found

11 / 30

11. How do you specify a pattern for a string in JSON Schema?

A) format

B) pattern

C) match

D) regex

12 / 30

12. What will JSON.stringify(true) return?

A) Throws an error

B) true

C) "True"

D) "true"

13 / 30

13. Which of the following formats can JSON be easily converted into for data visualization?

A) All of the above

B) CSV

C) XML

D) HTML

14 / 30

14. What is a safe alternative to eval() for parsing JSON in JavaScript?

A) JSON.debug()

B) JSON.parse()

C) JSON.stringify()

D) JSON.minify()

15 / 30

15. What is the difference between allOf and oneOf in JSON Schema?

A) oneOf requires at least one match, allOf requires none

B) allOf allows duplicates, oneOf does not

C) allOf validates all schemas, oneOf validates only one schema

D) allOf is for strings, oneOf is for arrays

16 / 30

16. What is the output of response.ok in a fetch() API call if the request is successful?

A) null

B) "ok"

C) 1

D) true

17 / 30

17. How do you handle very large JSON data efficiently in JavaScript?

A) Load the entire JSON object in memory

B) Both B and C

C) Split the JSON file into multiple smaller files

D) Use streaming parsers like JSONStream

18 / 30

18. What is a common vulnerability associated with parsing untrusted JSON?

A) JSON Injection

B) JSON Brute Force

C) JSON Flooding

D) JSON Parsing Loops

19 / 30

19. How do you specify that a JSON object must have at least one key in JSON Schema?

A) minProperties: 1

B) minKeys: 1

C) minItems: 1

D) required: true

20 / 30

20. What does the type keyword accept for mixed data types?

A) A single string

B) An array of types

C) A numeric range

D) A boolean flag

21 / 30

21. What does a JSON path debugger do?

A) Beautifies JSON

B) Validates JSON syntax

C) Converts JSON to CSV

D) Extracts specific values from JSON

22 / 30

22. What separates two key-value pairs in a JSON object?

A) Colon

B) Hyphen

C) Comma

D) Semicolon

23 / 30

23. Can a JSON object have duplicate keys?

A) Only in arrays

B) Yes

C) Only in nested objects

D) No

24 / 30

24. Which of the following JSON values is equivalent to "no value"?

A) null

B) none

C) ""

D) undefined

25 / 30

25. JSON is _______________.

A) Case-sensitive

B) None of the above

C) Partially case-sensitive

D) Case-insensitive

26 / 30

26. What does a JSON compressor do?

A) Removes unnecessary whitespace for smaller size

B) Beautifies JSON

C) Converts JSON to XML

D) Validates JSON

27 / 30

27. How do you check if a given JavaScript object is a valid JSON object?

A) Convert it to a string using JSON.stringify() and back using JSON.parse()

B) Use typeof to check if it is an object

C) Use Object.prototype.toString()

D) Use Array.isArray()

28 / 30

28. What is the purpose of application/json MIME type?

A) To parse JSON

B) To identify JSON data format

C) To convert JSON to XML

D) To define JSON structure

29 / 30

29. How can large nested JSON objects impact performance?

A) They improve network speed

B) They slow down parsing and increase memory usage

C) They reduce API latency

D) They make JSON more secure

30 / 30

30. What can be the root structure of a JSON document?

A) Only an object

B) Only an array

C) A string

D) Either an object or an array

Your score is

The average score is 41%

Rate Your Experience!

Anonymous feedback

Thank you for your feedback! We appreciate your input.

10 Minutes HTML Quiz Test Online

10 Minutes Angular Quiz Test Online

Bootstrap Quiz Test Online (30 random Questions)

10 Minutes MongoDB Quiz Test Online

10 Minutes CSS Quiz Test Online

HTML Quiz Test Online

Related