Like Ruby, Dart is a purely object-oriented (OO) language, so every variable in Dart points to an object and there are no primitive types as in Java or C#. Every variable is an instance of a class (that inherits from the base class Object) and has a type, and when uninitialized has the value null. But for ease-of-use Dart has built-in types for numbers, Booleans, and strings defined in dart:core, that look and behave like primitive types; that is, they can be made with literal values and have the basic operations you expect (to make it clear, we will use full typing in builtin_types.dart, but we could have used var as well).

A String (notice the capital) is a sequence of Unicode (UTF-16) characters, for example:

They can be indicated by paired ' or " (use "" when the string contains ' and vice versa). Adjacent string literals are concatenated. If you need multiline strings, use triple quotes ''' or """ (handy for defining chunks of HTML!).

Escape characters...