Introduction to php Android usage JSON XML difference_PHP tutorial

Introduction to using php Android JSON XML difference

Three elements of an app communication interface:
1. Interface address: (http://app.com/api.php?format=xml)
2. Interface file: (api.php handles some business logic)
3. Interface communication data


How App communicates
1.App sends http request to server
2. After processing, the server returns the data to the App
Different from b/s access method:
The address of the server page accessed in b/s mode can be seen in the address bar, but the address cannot be seen when accessed by app. It has been encapsulated.
The data returned in b/s mode is usually html, and the data format to be returned to the app is JSON and XML


JSON and XML
XML: Extensible Markup Language (Extensible Markup Language), which can be used to mark data and define data types. It is a


A source language that allows users to define their own markup language.
Features: XML can be customized by node and is cross-platform.

Root node




JSON (JavaScript Object Notation) is a lightweight data exchange format with good readability and convenience


Quick writing features. Data exchange between different platforms is possible. JSON has high compatibility and is completely independent of language text format


Mode. These properties make JSON an ideal data exchange language.


The first one is to parse out the string: "s" (there are few people using this format and it is not easy to understand)
The second method is to parse out the array {"title":"david","from":"qingdao","decrip":"hello"} (key:value is


easy to understand, so this is commonly used)


The difference between xml and json:
1. Readability: The xml structure is clear and the json output is similar to a string, so the xml is readable
2. PHP generates data: How PHP generates json data: json_encode($arr);
How to generate xml data: encapsulate multiple strings and output them together.
json only uses one function, which is very convenient;
3.Transmission speed:
JSON has no tags and the data is small, so the transmission is fast.


app interface function:
1. Get data: Get data from the database or cache, and then return it to the client through the interface data. For example: add
to main interface data

load.
2. Submit data: (get post), submit data to the server through the interface, and then the server stores it in the database for processing, or other operations. Class


Similar to a web submission form. Such as feedback.


Version upgrade interface: Submit the current version data and obtain whether the data is updated.