Comparison of XML, JSON, protocolbuffer, and Lua features

	XML	JSON	PB	Lua
Data structure support	Complex Structure	Simple Structure	Complex Structure	Complex Structure
Data Storage Method	Text	Text	Binary	Text
Data storage size	Large	Average	Small	Average
Resolution Efficiency	Slow	Average	Fast	Faster
Language Support level	Many	Multiple	C ++/Java/Python	Multiple
Development difficulty | tedious	Tedious	Simple	Simple	Relatively cumbersome
Learning cost	Low	Low	Low	High
Applicability	Data Exchange	Data Exchange	Data Exchange	Data storage and Script Processing

Note:
For large applications, we recommend that you use xml for data exchange. After all, xml data is structured. This not only allows you to specify a vocabulary that defines the elements in the document, but also allows you to specify the relationship between elements. Of course, json data is also in this format, but in the data storage of large applications, its storage efficiency seems to be insufficient.
But for a small application, if it is a web application, it is a good choice to select json, because you do not need to worry about the annoying methods and attributes when using it, because you operate on json is equivalent to operating an array with an indefinite dimension. How can a language operate on an array? In addition, most languages have begun to encapsulate some good functions and classes for it, therefore, you can easily implement data conversion by calling the database method.

After an SMS system was built, we found that json was originally like this.