Top 50 JSON Interview Questions with Answers

Post Views: 9

What does JSON stand for?
a) JavaScript Object Notation
b) Java Syntax Object Notation
c) JSON Object Notation
d) None of the above

Answer: a) JavaScript Object Notation

What is JSON used for?
a) Data interchange format
b) JavaScript plugin
c) Code execution
d) HTML markup

Answer: a) Data interchange format

Which of the following data types can be used in JSON?
a) Strings
b) Numbers
c) Booleans
d) All of the above

Answer: d) All of the above

What is the maximum depth limit in JSON?
a) There is no limit
b) 10 levels
c) 100 levels
d) 1000 levels

Answer: a) There is no limit

Which of the following is NOT a valid JSON value?
a) Null
b) Undefined
c) Object
d) Array

Answer: b) Undefined

What does the toJSON() method do?
a) Converts a JSON string into an object
b) Converts an object into a JSON string
c) Parses a JSON file
d) None of the above

Answer: b) Converts an object into a JSON string

Which method is used to parse JSON?
a) parseJSON()
b) parse()
c) fromJSON()
d) toJSON()

Answer: b) parse()

What is JSONP used for?
a) Cross-domain requests
b) Client-side validation
c) Server-side scripting
d) None of the above

Answer: a) Cross-domain requests

Which symbol represents the start and end of a JSON object?
a) {}
b) []
c) ()
d) <>

Answer: a) {}

Which symbol separates the key and value pair in a JSON object?
a) :
b) ;
c) ,
d) |

Answer: a) :

What is the MIME type for JSON?
a) application/javascript
b) application/xml
c) application/json
d) text/json

Answer: c) application/json

Which JavaScript method is used to stringify an object into JSON format?
a) toJSONString()
b) parse()
c) stringify()
d) fromJSON()

Answer: c) stringify()

Which of the following is NOT a valid JSON data type?
a) Decimal
b) String
c) Number
d) Object

Answer: a) Decimal

Which of the following is used to represent arrays in JSON?
a) {}
b) []
c) ()
d) <>

Answer: b) []

Which of the following is NOT a valid way to create a JSON object?
a) var obj = { name: “John”, age: 30 };
b) var obj = new Object();
obj.name = “John”;
obj.age = 30;
c) var obj = {“name”: “John”, “age”: 30};
d) var obj = [ “name”: “John”, “age”: 30];

Answer: d) var obj = [ “name”: “John”, “age”: 30];

What is JSON Schema used for?
a) To validate JSON data
b) To convert JSON to XML
c) To create JSON objects
d) None of the above

Answer: a) To validate JSON data

Which of the following is NOT a valid JSON Schema data type?
a) integer
b) boolean
c) real
d) string

Answer: c) real

What is JSON-RPC used for?
a) Remote procedure calls
b) Server-side scripting
c) Client-side validation
d) None of the above

Answer: a) Remote procedure calls

What is JSON-B used for?
a) Serializing Java objects into JSON
b) Parsing JSON data into Java objects
c) Validating JSON data
d) None of the above

Answer: a) Serializing Java objects into JSON

What does the @JsonIgnore annotation do in JSON-B?
a) Excludes a field from serialization
b) Includes a field in serialization
c) Validates a field value
d) None of the above

Answer: a) Excludes a field from serialization

What is JSON-LD used for?
a) To embed context data within JSON
b) To retrieve data from external sources
c) To create JSON objects
d) None of the above

Answer: a) To embed context data within JSON

Which method is used to format JSON data for readability?
a) json_format()
b) pretty_print()
c) format()
d) None of the above

Answer: b) pretty_print()

Which of the following is valid JSON syntax?
a) { “name”: “John”, “age”: 30, };
b) { name: “John”, age: 30 }
c) {“name”: “John”, “age”: 30 }
d) None of the above

Answer: c) {“name”: “John”, “age”: 30 }

Which of the following characters is NOT escaped in JSON?
a) Backspace
b) Form feed
c) Double quote
d) Single quote

Answer: d) Single quote

What is the JavaScript method used to evaluate a JSON string into an object?
a) evalJSON()
b) parseJSON()
c) executeJSON()
d) None of the above

Answer: b) parseJSON()

Which of the following is NOT a property of the JSON object in JavaScript?
a) JSON.parse()
b) JSON.stringify()
c) JSON.serialize()
d) None of the above

Answer: c) JSON.serialize()

What does the reviver parameter do in the JSON.parse() method?
a) It is used to parse nested JSON data
b) It is used to modify the parsed data
c) It is used to validate the parsed data
d) None of the above

Answer: b) It is used to modify the parsed data

Which of the following is a correct JSON data structure?
a) {“name”: “John”, “age”: 30, “isMarried”: true}
b) {name: “John”, age: 30, isMarried: true}
c) {name: “John”, age: 30, isMarried: True}
d) None of the above

Answer: a) {“name”: “John”, “age”: 30, “isMarried”: true}

Which of the following is NOT a valid way to get a JSON array from a string?
a) JSON.parse(string)
b) eval(string)
c) string.toJSON()
d) None of the above

Answer: c) string.toJSON()

What is the difference between JSON and XML?
a) JSON is easier to read and parse
b) XML is more suited for complex data structures
c) JSON is more widely used
d) All of the above

Answer: d) All of the above

Which of the following is NOT a valid way to create a JSON object in Java?
a) JSONObject obj = new JSONObject();
obj.put(“name”, “John”);
obj.put(“age”, 30);
b) Map, Object> map = new HashMap<>();
map.put(“name”, “John”);
map.put(“age”, 30);
JSONObject obj = new JSONObject(map);
c) String json = “{\”name\”:\”John\”,\”age\”:30}”;
JSONObject obj = new JSONObject(json);
d) None of the above

Answer: d) None of the above

What is the syntax to access a property in a JSON object?
a) object.property
b) object[“property”]
c) object->property
d) None of the above

Answer: b) object[“property”]

Which of the following is used to store a JSON object in a cookie?
a) JSON.parse()
b) JSON.stringify()
c) JSON.serialize()
d) None of the above

Answer: b) JSON.stringify()

What is JSON Web Token (JWT) used for?
a) Authentication and authorization
b) Data serialization
c) Remote procedure calls
d) None of the above

Answer: a) Authentication and authorization

Which of the following is a valid JSON example of a nested object?
a) {“name”:”John”,”address”:{“street”:”123 Main St”,”city”:”Anytown”,”state”:”CA”}}
b) {“name”:”John”,”address”:[“123 Main St”,”Anytown”,”CA”]}
c) {“name”:”John”,”address”:{“street”:”123 Main St”},”address”:{“city”:”Anytown”},”address”:{“state”:”CA”}}
d) None of the above

Answer: a) {“name”:”John”,”address”:{“street”:”123 Main St”,”city”:”Anytown”,”state”:”CA”}}

What is the syntax to access an element in a JSON array?
a) array[index]
b) array[“index”]
c) array->index
d) None of the above

Answer: a) array[index]

Which of the following is NOT a valid way to create a JSON object in Python?
a) data = {“name”: “John”, “age”: 30}
json_data = json.dumps(data)
b) data = json.load(“data.json”)
c) data = json.loads(‘{“name”: “John”, “age”: 30}’)
d) None of the above

Answer: b) data = json.load(“data.json”)

Which of the following is NOT a valid way to create a JSON array in JavaScript?
a) var array = [“John”, 30, true];
b) var array = new Array(“John”, 30, true);
c) var array = {
0: “John”,
1: 30,
2: true
};
d) None of the above

Answer: c) var array = {0: “John”, 1: 30, 2: true}

What is the difference between a JSON object and a JavaScript object?
a) There is no difference
b) A JSON object is a string, while a JavaScript object is an actual object
c) A JavaScript object is defined using curly braces, while a JSON object is defined using quotes
d) None of the above

Answer: b) A JSON object is a string, while a JavaScript object is an actual object

What is JSON streaming used for?
a) To reduce memory consumption when working with large data sets
b) To validate JSON data
c) To create JSON objects
d) None of the above

Answer: a) To reduce memory consumption when working with large data sets

What is the syntax to add a property to a JSON object?
a) object.newproperty = value;
b) object[“newproperty”] = value;
c) object.addproperty(value);
d) None of the above

Answer: b) object[“newproperty”] = value;

Which of the following is NOT a valid way to create a JSON object in Ruby?
a) data = {“name” => “John”, “age” => 30}
json_data = JSON.dump(data)
b) data = JSON.parse(‘{“name”: “John”, “age”: 30}’)
c) data = JSON.load(‘data.json’)
d) None of the above

Answer: c) data = JSON.load(‘data.json’)

What does the JSON.stringify() method return?
a) A JSON string
b) A JSON object
c) A JavaScript object
d) None of the above

Answer: a) A JSON string

Which of the following is a correct JSON data structure for an array of objects?
a) [{“name”: “John”, “age”: 30}, {“name”: “Jane”, “age”: 25}]
b) {0: {“name”: “John”, “age”: 30}, 1: {“name”: “Jane”, “age”: 25}}
c) [“name”: “John”, “age”: 30], [“name”: “Jane”, “age”: 25]
d) None of the above

Answer: a) [{“name”: “John”, “age”: 30}, {“name”: “Jane”, “age”: 25}]

Which of the following is valid JSON syntax for an array of numbers?
a) [1, 2, 3.14]
b) [“1”, “2”, “3.14”]
c) [“one”, “two”, “three”]
d) None of the above

Answer: a) [1, 2, 3.14]

What is the syntax to remove a property from a JSON object?
a) delete object.property;
b) object.remove(property);
c) object[“property”] = null;
d) None of the above

Answer: a) delete object.property;

Which of the following is NOT a valid way to create a JSON object in C#?
a) JObject obj = new JObject();
obj.Add(“name”, “John”);
obj.Add(“age”, 30);
b) JObject obj = JObject.Parse(‘{“name”: “John”, “age”: 30}’);
c) string json = “{\”name\”:\”John\”,\”age\”:30}”;
JObject obj = JsonConvert.DeserializeObjectObject>(json);
d) None of the above

Answer: d) None of the above

What is the difference between JSON and BSON?
a) JSON is more widely used
b) BSON is more suited for complex data structures
c) BSON is faster to parse
d) All of the above

Answer: c) BSON is faster to parse

What is the maximum length for a JSON string?
a) 4GB
b) 1GB
c) 16MB
d) 10MB

Answer: c) 16MB

Which of the following is NOT a valid way to retrieve data from a JSON object?
a) object.property
b) object[“property”]
c) object.getProperty()
d) None of the above

Answer: c) object.getProperty()

Author
Recent Posts

Ashwani Kumar

Sr. Software Engineer at Cotocus Private Limited

There is no end to education. It is not that you read a book, pass an examination, and finish with education. The whole of life, from the moment you are born to the moment you die, is a process of learning.