17.10.2 Instance variable initializers

When an instance constructor has no constructor initializer, or it has a
constructor initializer of the form
base(?), that constructor implicitly performs the initializations specified
by the variable-initializers of the
instance fields declared in its class. This corresponds to a sequence of
assignments that are executed immediately
upon entry to the constructor and before the implicit invocation of the
direct base class constructor. The variable
initializers are executed in the textual order in which they appear in the
class declaration.