Summary of the basic usage of YAML configuration files

1. Introduction

• YAML is a recursive acronym for "YAML Ain't a Markup Language" (YAML is not a markup language). When developing this language, YAML actually meant: "Yet Another Markup Language" (still a markup language).
• It is very suitable for data-centric configuration files.

2. Basic grammatical structure

• key: value; key: there is a space between value
• Case Sensitive
• Use indentation to indicate hierarchical relationships
• Tabs are not allowed for indentation, only spaces are allowed (but you can rest assured to use tabs for indentation in idea, there is no problem at present)
• The number of indented spaces is not important, as long as the elements of the same level are aligned to the left
• '#' means comment
• String is not to be quoted, if you want to add, ""and ''a string representing the content will not be escaped or escaped.
  • The ''content of the single quote string will not be escaped, for example, it ' \n 'will output the string \n
  • Double quotes ""string contents are escaped, for example "\n "will \ n escape the line feed output transducer

1. When the data type is literal

• Literal: A single, indivisible value. date, boolean, string, number, null

:( syntax k:and vyou must be a space between.)

#`k:`与`v`之间必须加空格
k: v

2. When the data type is a collection of objects and key-value pairs

• Collection of objects and key-value pairs: map, hash, set, object

The grammar is: ( no space can be added between k:and when writing in a line, and a vspace must be added between k:and when writing in general v)

#行内写法：（行内写法时`k:`与`v`之间可以不加空格）  
k: {
    
    k1:v1,k2:v2,k3:v3}
#或一般写法：（一般写法时`k:`与`v`之间必须加空格）
k: 
  k1: v1
  k2: v2
  k3: v3

3. When the data type is an array, a set of values ​​in order

• Array, a set of values ​​in order: array, list, queue

The syntax is :( k:and vbetween, -and vall must be a space between)

#`k:`与`v`之间，`-`与`v`之间都必须加空格
行内写法：  k: [v1,v2,v3]
#或者
k:
 - v1
 - v2
 - v3

Practical example:

Output result: