1. What is JSON?

JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate.

2. What is the file extension for JSON?

The common file extension for JSON files is .json.

3. How is JSON different from JavaScript object literal notation?

JSON is a data interchange format, while JavaScript object literal notation is used to define objects within JavaScript code. JSON is a subset of JavaScript object literal notation.

4. What are the basic data types supported by JSON?

JSON supports strings, numbers, objects, arrays, booleans, and null.

5. How to represent a string in JSON?

Strings in JSON are represented using double-quoted Unicode characters.

6. How to represent a number in JSON?

Numbers in JSON can be integers or floating-point, represented without quotes.

7. What is a JSON object?

A JSON object is an unordered collection of key-value pairs, where keys are strings and values can be strings, numbers, objects, arrays, booleans, or null.

8. How to represent an object in JSON?

An object in JSON is enclosed in curly braces {}, with key-value pairs separated by commas.

9. What is a JSON array?

A JSON array is an ordered list of values, represented by square brackets [].

10. How to represent an array in JSON?

An array in JSON is enclosed in square brackets [], and elements are separated by commas.

11. What is the purpose of JSON Schema?

JSON Schema is used to describe the structure and validation constraints of JSON documents.

12. How to comment in JSON?

JSON itself does not support comments, but some JSON parsers and preprocessors allow single-line or multiline comments.

13. How to escape characters in a JSON string?

Use a backslash \ to escape characters in a JSON string. For example, \” represents a double quote.

14. What is JSONP (JSON with Padding)?

JSONP is a technique for loading JSON data from a different domain by using a script tag and a callback function.

15. How to pretty-print JSON?

Use indentation and line breaks to format JSON in a human-readable way.

16. How to convert a JSON string to a JavaScript object?

Use JSON.parse() to convert a JSON string to a JavaScript object.

17. How to convert a JavaScript object to a JSON string?

Use JSON.stringify() to convert a JavaScript object to a JSON string.

18. What is the purpose of the MIME type “application/json”?

The MIME type “application/json” is used to indicate that the content is in JSON format.

19. How to handle dates in JSON?

Use a string representation of the date conforming to a standard format (e.g., ISO 8601).

20. How to handle nested JSON objects?

Nested JSON objects are represented by including objects as values within other objects.

21. What is JSON Web Token (JWT)?

JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties.

22. What is JSONPath?

JSONPath is a query language for JSON that allows you to navigate and query JSON structures.

23. How to handle errors in JSON parsing?

Use try…catch blocks when using JSON.parse() to handle errors during JSON parsing.

24. What is the difference between JSON and XML?

JSON is a lightweight data interchange format with simpler syntax, while XML is a markup language with more verbose syntax.

25. How to remove an element from a JSON object?

To remove a property from a JSON object, use the delete keyword.

26. How to validate JSON against a JSON Schema?

Use JSON Schema validators or online validation tools to validate JSON against a schema.

27. What is JSON-RPC?

JSON-RPC is a remote procedure call (RPC) protocol encoded in JSON.

28. How to pretty-print JSON in different programming languages?

Various programming languages provide libraries or functions for pretty-printing JSON, like json.dumps() in Python or JSON.stringify() in JavaScript.

29. What is JSON Web Encryption (JWE)?

JSON Web Encryption (JWE) is a standard for encrypting JSON data.

30. How to handle empty or null values in JSON?

Represent empty values as null in JSON.

31. What is JSON-LD (JSON Linked Data)?

JSON-LD is a format for expressing linked data using JSON.

32. How to handle case sensitivity in JSON keys?

JSON keys are case-sensitive, so ensure consistency in key naming.

33. What is the purpose of the JSON merge patch?

JSON merge patch is a way to describe changes to a JSON document and is often used in partial updates.

34. How to handle large JSON files efficiently?

Use streaming JSON parsers or process the JSON data in chunks to handle large files efficiently.

35. What is JSONiq?

JSONiq is a query language specifically designed for JSON data.

36. How to encode special characters in JSON?

Most special characters do not require encoding in JSON, but use \uXXXX for Unicode characters.

## 37. What is BSON (Binary JSON)?

BSON is a binary-encoded serialization format similar to JSON, but designed for efficiency in storage and traversal.

38. How to handle circular references in JSON objects?

Use a library that supports handling circular references or manually break the circular reference before serialization.

39. How to fetch and parse JSON data in JavaScript?

Use the fetch() API to make a request for JSON data and JSON.parse() to parse the JSON response.

40. How to convert a JSON array to a JavaScript array?

Use JSON.parse() to convert a JSON array string to a JavaScript array.

41. What is JSON Streaming?

JSON Streaming is a technique for progressively sending JSON data as it’s produced, without waiting for the entire data set to be generated.

42. How to filter JSON data in JavaScript?

Use array methods like filter() to filter JSON arrays based on specific criteria.

43. What is the purpose of the reviver function in JSON.parse()?

The reviver function allows you to transform the parsed JSON object, providing custom behavior during parsing.

44. How to format dates in JSON?

Use a standardized date format, such as ISO 8601, to represent dates in JSON.

45. How to handle cross-origin requests in JSON?

Use CORS (Cross-Origin Resource Sharing) headers on the server to allow cross-origin requests.

46. What is JSONB?

JSONB is a binary format for JSON data storage in databases, providing efficient indexing and querying.

47. How to merge two JSON objects in JavaScript?

Use the Object.assign() method or the spread operator ({…}) to merge two JSON objects in JavaScript.

48. How to handle deep nesting in JSON?

Use proper data modeling, and consider flattening or restructuring data to avoid deep nesting.

49. What is JSON Lines (JSONL)?

JSON Lines is a format for storing JSON data, where each line is a valid JSON value.

50. What is JSON with Padding (JSONP)?

JSONP is a technique to overcome the same-origin policy limitation in web browsers when making cross-domain requests by using script tags and callbacks.