JSON 面试题与答案
相关差异对比
问题 1. Who is the Father of JSON ?
Douglas Crockford is the Creator or Father of JSON.
问题 2. What is JSON?
JSON full form is 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.
问题 3. What is the file extension of JSON?
The JSON filename extension is .json.
问题 4. Explain JSON with php.
Json 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.
Example:
$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
问题 5. Why use JSON over XML?
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
用户评价最有帮助的内容：
- Who is the Father of JSON ?
- What is the file extension of JSON?
- What is JSON?
- Why use JSON over XML?
- Explain JSON with php.