Common data types:
In Dart, arrays are list objects, so most people just call them lists
In general, Map is a key-value pair related object. Keys and values can be any type of object. Each key appears only once, and a value can appear multiple times.
The type of data that is not used in our project (not used):
Rune is a UTF-32 encoded string. It can be converted to symbolic expressions by text or to represent specific text.
The Symbol object represents the operator or identifier declared in the Dart program. You may never need to use symbols, but they are very useful for APIs that reference identifiers by name, because zooming out changes the identifier name without changing the identifier symbol. To get the symbol of the identifier, use the symbolic text, which is just the # followed by the identifier:
Symbols in Dart are indicated by the beginning of #, and you don’t need to know about this in the entry phase, and you may never use it.