New features in Delphi 2009

JSON (JavaScript Object notation) is similar to XML;

It started with JavaScript and was supported by multiple languages, and it became one of the new features of Delphi 2009.

If there is a section of XML: <id>2</id> <name> John </name> <age>99</age> with JSON can be expressed as: {"id": 2, "name": " John ", Age": 99}

JSON is extremely convenient to use in JavaScript, such as:

Example 1: Data = {"id":2, "name":"张三 ", "age":99};
str = Data.id;　　　//2
str = Data.name;　　//张三
str = Data["name"]; //张三 //Example 2: Data = {"id":2, "name":{"FirstName":"张 ", "LastName":"三"}, "age":99};
str = Data.name.FirstName;　//张
str = Data["name"]["FirstName"]; //张 //Example 3:/ Data =
[
　{"name":"张三", "age":9},
　{"name":"李四", "age":19},
　{"name":"王五", "age":29}
]
str = Data[2].name;　//王五
str = Data[2]["name"]; //王五 /Example 4: The Data = {"name":"张三", "age":19, "like":["游戏","足球"]};
str = Data.like[1];　　//足球
str = Data["like"][1]; //足球 JavaScript code in this example can also be debugged in Delphi, see:

Http://www.cnblogs.com/del/archive/2008/08/06/1261580.html

In JSON:

Elements and values are separated by a colon ":"

Elements and elements are separated by commas ","

{} is an object that can be nested in layers

[] represents an array, and the array elements are separated by commas ","

Values can be string, number, object, array, True, false, null; Where string to use double quotes (and language can be in single quotes)

You can use an escape character similar to the C language in string

Number can use the scientific counting method