YAML's most basic syntax

As Yaml represents, Yaml Ain ' t Markup Language,yaml is a concise, non-markup language. YAML is data-centric, uses whitespace, indents, and organizes data into branches, making the presentation more concise and readable.

While learning the rules, you can practice the basic rules in the online demo-yaml conversion JSON Web page.

YAML has the following basic rules:
1, Case sensitive
2. Use indentation to represent hierarchical relationships
3, prohibit the use of tab indentation, you can only use the space key
4. There is no limit to the indentation length, as long as the element alignment indicates that the elements belong to a hierarchy.
5. Use # to indicate comments
6. String can be used without quotation marks three kinds of data structure

1, map, hash list
Use a colon (:) to denote a key-value pair, and all key-value pairs of the same indentation belong to a map, for example:

# Yaml means
age:12
Name:huang

# Corresponds to the JSON representation
{' age ': ', ' name ': ' Huang '}

You can also write a map on one line:

# Yaml means
{age:12,name:huang}

# corresponds to the JSON representation
{' age ': ', ' name ': ' Huang '}

2, List, array
Use a hyphen (-) to indicate:

# Yaml means
-a
-B
-

# corresponds
to the JSON representation [' A ', ' B ', 12]

It can also be written in one line:

# Yaml means
[a,b,c]

# Corresponds to JSON representation
[' A ', ' B ', ' C ']

3, scalar, pure quantity
The smallest unit of data can no longer be split. Data Structure Nesting

The elements of map and list can be another map or list or a pure quantity. There are 4 common nesting of data:
1. Map nested map

# YAML means
websites:
 YAML:yaml.org 
 ruby:ruby-lang.org 
 Python:python.org 
 Perl:use.perl.org 

# corresponds to the JSON representation
{websites: 
   {YAML: ' yaml.org ',
     Ruby: ' ruby-lang.org ',
     Python: ' python.org ',
     Perl: ' use.perl.org '}

2. Map nested list

# Yaml means
languages:
 -Ruby
 -Perl
 -Python 
 -C

# corresponds to JSON notation
{languages: [' Ruby ', ' Perl ', ' Python ', ' C ']}

3. List nested list

# Yaml means
--
  Ruby
  -Perl
  -Python 
- 
  -C
  -C + +
  -Java

# corresponds to the JSON representation
[[' Ruby ', ' Perl ', ' Python '], [' C ', ' C + + ', ' Java ']

In addition, you can also indicate the structure as follows

# method 2
--Ruby
  -Perl
  -Python- 
-C
  -C + +
  -Java

# Method 3
-[Ruby,perl,python]
-[C,c++, Java

4. List nested map

# YAML Representation
-
  id:1
  name:huang
-
  id:2
  name:liao

# Corresponds to JSON representation
[{id:1, name: ' Huang '}, {id:2, Name: ' Liao '}]