Some bad thing about XML is that it can happen that 99% of a XML file content is used just for the XML tags and the rest for the data to be stored. Therefore some other formats are commonly used:
Json stands for Java Script Object Notation. It is a way to format data using Javascript syntax. This is why it can be easily be imported into Javascript using the Javascript's eval() function. To not get a syntax error brackets need to be used:
var j = eval ("(" + <string variable containing json>
+ ")");
However since a files could contain also code instead of just data, json files are usually be parsed and not executed.
json is used by firefox to hold the bookmark backups ~/.mozilla/firefox/<some random characters>.default/bookmarkbackups
Python supports json https://docs.python.org/3/library/json.html. The concept is that a json data represented in a string can be converted in a python structure and back.
Python has also json functionality in its standard library.
To validate json the text can be copied and pasted into https://jsonlint.com
Json assigns a value to a name:
"<name>
" : "<value>
"
Multiple name/value pairs can be grouped
{ "<name1>
":"<value1>
" , "<name2>
":"<value2>
" }
or put into an array
{ "<array name>
": [ { "<name1>
":"<value1>
" }, { "<name2>
":"<value2>
" } ] }