JSON preliminary understanding

JSON Preliminary understanding

Full name ：Javascript Object Notation

It's a text format for data exchange , stay 2001 Was proposed in , The purpose is to replace the heavy XML.

It is a transmission format supported by both front and back ends .

JSON It's an independent language , Essentially a string , Not object .

matters needing attention ：
1. String must use double quotes , You can't use single quotes .
2. The last value cannot be followed by a comma .
3. Must be decimal , Cannot be hexadecimal .
4. The value of the original type is only 4 Kind of ： character string , The number , Boor and null. Out of commission NaN,Infinity and undefined.
5.JSON You can't put it in the function
6.JSON In the process of data transmission, it must be String type .

JSON The transformation method of ：
JSON.stringify( ) To JSON Format
JSON.parse( ) hold JSON Format to JS object

JSON How to write it ：

{"name":" value "}

XML How to write it ：
XML Customizable labels

<name> value </name>