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Following is an introduction to the YAML syntax. If you are familiar with YAML, skip to the TYPO3 specific information:
A good general introduction to YAML syntax, basic data types, etc.:
The TYPO3 coding guidelines for YAML define some basic rules to be used in the TYPO3 core and extensions. Additionally, yaml has general syntax rules.
Indenting with 2 spaces (not tabs). Spaces MUST be used. You MUST use the correct indenting level.
All text is case-sensitive
Enclose strings with single quotes ('')
The following MUST be adhered to in order to produce valid syntax:
Use spaces, not tabs to indent
Identing is not optional. It is used to define the hierarchy of the data
To get a better understanding of YAML, you might want to compare YAML with PHP arrays:
$a = [ 'key1' => 'value', 'key2' => [ 'key2_1' => 'value' ]; $b = [ 'apples', 'oranges', 'bananas' ];
# mapping (key / value pairs) a: key1: 'value' key2: key2_1: 'value' # sequence (list) b: - 'apples' - 'oranges' - 'bananas'