JSON interview questions and answer

Questions : 1What is The JSON(JavaScript Object Notation) ?
Answers : 1
JavaScript Object Notation(JSON) is a lightweight text-based open standard designed for human-readable data interchange. It is derived from the JavaScript programming language for representing simple data structures and associative arrays, called objects. And JSON is language-independent, with parsers available for virtually every programming language. Uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python,php
The JSON format is often used for serializing and transmitting structured data over a network connection. When third party data interchane(REST Services) then JSON may used there LIKE SHOP .It is primarily used to transmit data between a server and web application, serving as an alternative to XML.
  
Questions : 2Who is the Father or creater of JSON ?
Answers : 2Douglas Crockford called as the Father of JSON
  
Questions : 3what the file extension of JSON
Answers : 3The JSON filename extension is .json.
  
Questions : 4Explain Json with php
Answer : 4Json is too much easy with php There is no installation needed to use these functions; they are part of the PHP core. nothing more need to know just only use { ,[ and create json format string and use three php function json_encode() to get JSON representation of a value, json_decode() for Decodes a JSON string, ¦json_last_error() to get the last error occurred in process.

write your desire string in below format and use php funtions :

$string='{
"firstName": "Rohit",
"lastName": "Singh",
"age": 26,
"address": {
"streetAddress": "Mira Road Thane ",
"city": "Mumbai",
"state": "maharshtra",
"postalCode": "401107"
},
"phoneNumber": [
{ "type": "home", "number": "022 333-1234" },
{ "type": "fax", "number": "022 444-4567" }
]
}';

$decodeString = json_decode($string);
echo 'First Name - '.$decode->{"firstName"};
echo 'Last Name - '.$decode->{"lastName"};
echo 'Address - '.$decode->{"address"}->{"streetAddress"};

Out put : Print below

First Name - Rohit
Last Name - Singh
Address - Mira Road Thane
  
Questions : 5Why Use JSON over XML
Answers : 5• Lighter and faster than XML as on-the-wire data format
• JSON objects are typed while XML data is typeless
> JSON types: string, number, array, boolean,
> XML data are all string
• Native data form for JavaScript code
> Data is readily accessible as JSON objects in your JavaScript
code vs. XML data needed to be parsed and assigned to variables through tedious DOM APIs
> Retrieving values is as easy as reading from an object property in your JavaScript code
  
Questions : 6Explain JSON Structures
Answers : 6• A collection of name/value pairs
> In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list, or associative array
• An ordered list of values
> In most languages, this is realized as an array, vector, list, or sequence
• These are universal data structures supported
• A JSON object is an unordered set of name/value pairs
• A JSON object begins with { (left brace) and ends with } (right brace)
• Each name is followed by : (colon) and the name/value pairs are separated by , (comma)
  
Questions : 7Compare JSON with JavaScript
Answers : 7• JSON is a subset of the object literal notation of JavaScript
> JSON can be used in the JavaScript language with no muss or fuss
Example: JSON Object
var myJSONObject = {"bindings": [ {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"},
{"ircEvent": "PRIVMSG", "method": "deleteURI", "regex": "^delete.*"},
{"ircEvent": "PRIVMSG", "method": "randomURI", "regex": "^random.*"}
]
};
• In this example, a JSON JavaScript object is created
containing a single member "bindings", which contains
an array containing three objects, each containing
"ircEvent", "method", and "regex" members
• Members can be retrieved using dot or subscript
operators myJSONObject.bindings[0].method // "newURI"
Text to Object Conversion in
JavaScript code
var myObject = eval('(' + myJSONtext + ')');
• To convert a JSON text into an JSON object, use
the eval() function > eval() invokes the JavaScript compiler
> Since JSON is a proper subset of JavaScript, the compiler will
correctly parse the text and produce an object structure
  
Questions : 8what the Security and JSON Parser
Answers : 8Security and JSON Parser to understand by below examples
// Include http://www.json.org/json.js
var myObject = myJSONtext.parseJSON();
• eval() can compile and execute any JavaScript program, so there can be security issues (cross-site scripting)
> Use eval() when the source can be trusted
• When security is a concern - the source cannot be trusted -, it is better to use a JSON parser
> A JSON parser will only recognize JSON text and so is much safer
Object to Text Conversion
var myJSONText = myObject.toJSONString();
• You can convert JSON object into JSON text
• JSON does not support cyclic data structure
> Do not give cyclical structures to the JSON stringifier
  
Questions : 9Do you know JSON Tools for Java Developer
Answers : 9Ya some of JSON tool for java developer is
• Parser
> Parse JSON text files and convert these to a Java model
• Renderer
> Render a Java representation into text
• Serializer
> Serialize plain POJO clusters to a JSON representation
• Validator
> Validate the contents of a JSON file using a JSON schema
JSONObject Java Class
• A JSONObject is an unordered collection of name/value pairs
• The put methods adds a name/value pair to an object
• The texts produced by the toString methods strictly conform to the JSON syntax rules
myString = new JSONObject().put("JSON", "Hello, World!").toString();
// myString is {"JSON": "Hello, World"}
  
Questions : 10How to Generate or Send JSON Data at the Server Side
Answers : 10• Create JSONObject Java object
• Add name and value pairs using put method
• Convert it to String type using toString method and send it to the client with content-type as "text/xml" or "text/plain"
myString = new JSONObject().put("JSON", "Hello, World!").toString();
// myString is {"JSON": "Hello, World"}
  
Questions : 11How to Receive JSON Data at the Client Side
Answers : 11• JSON data is received as a string
• Calling eval() will generate JSON object in JavaScript code
> var JSONdata = eval(req.responseText);
• Once you have JSON object, you can use . notation to access its properties
> var name = JSONdata.name;
> var address = JSONdata.addresses[3];
> var streetname = JSONdata.addresses[3].street;
  
Questions : 12How to Generate/Send JSON Data at the Client Side
Answers : 12• Create JSON JavaScript object
• Use "POST" HTTP method in the open method of the XMLHttpRequest object
• Pass JSON JavaScript object in the send method of XMLHttpRequest object
var carAsJSON = JSON.stringify(car);
var url = "JSONExample?timeStamp=" + new Date().getTime(); createXMLHttpRequest();
xmlHttp.open("POST", url, true);
xmlHttp.onreadystatechange = handleStateChange;
xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlHttp.send(carAsJSON);
  
Questions : 13How to Receive JSON Data at the Server Side
Answers : 13• Read the JSON data as a String type
• Create JSONObject Java object from the string String json = readJSONStringFromRequestBody(request);
//Use the JSON-Java binding library to create a JSON object in Java JSONObject jsonObject = null;
try {
jsonObject = new JSONObject(json);
}
catch(ParseException pe) {
}
  
Questions : 14What is JSON-RPC? What is JSON-RPC-Java?
Answers : 14• JSON-RPC is a simple remote procedure call protocol similar to XML-RPC although it uses the lightweight JSON format instead of XML
• JSON-RPC-Java is a Java implementation of the JSON-RPC protocol
  
Questions : 15Why JSON-RPC-Java?
Answers : 15• It allows you to transparently call server-side Java code from JavaScript with an included lightweight JSON-RPC JavaScript client
• It is designed to run in a Servlet container such as Tomcat and can be used with J2EE Application servers to allow calling of plain Java or EJB methods from within a JavaScript DHTML web application
  
Questions : 16Features of JSON-RPC-Java
Answers : 16• Dynamically call server-side Java methods from JavaScript DHTML web applications. No Page reloading.
• Asynchronous communications.
• Transparently maps Java objects to JavaScript objects.
• Lightweight protocol similar to XML-RPC although much faster.
• Leverages J2EE security model with session specific exporting of objects.
• Supports Internet Explorer, Mozilla, Firefox, Safari, Opera and Konqueror

Comments

  1. hitesh kumar25 October 2017 at 07:50

    Your JSON Interview Questions is more useful than these websites interview questions

    JSON Interview Questions

    ReplyDelete

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