A data type defines what the possible values an expression, such as a variable, operator or a function call, might use.

The template_engine supports several default DataTypes.

You can adopt existing DataTypes or add your own custom DataTypes by manipulating the TemplateEngine.dataTypes field.
See example

description:	A form of data containing a sequence of characters
syntax:	A string is declared with a chain of characters, surrounded by two single (') or double (") quotes to indicate the start and end of a string. In example: 'Hello' or "Hello"
example:	string_test.dart

description:	A form of data to express the size of something.
syntax:	A number is declared with: * optional: positive (e.g. +12) or negative (e.g. -12) prefix or no prefix (12=positive) * one or more digits (e.g. 12) * optional fragments (e.g. 0.12) * optional: scientific notation: the letter E is used to mean"10 to the power of." (e.g. 1.314E+1 means 1.314 * 10^1which is 13.14).
example:	num_test.dart

description:	A form of data with only two possible values: true or false
syntax:	A boolean is declared with the word true or false. The letters are case insensitive.
example:	bool_test.dart