12.2 Default values?Static variables.

?Array elements.
The default value of a variable depends on the type of the variable and is
determined as follows:
?For a variable of a value-type, the default value is the same as the
value computed by the value-type.s
default constructor (?1.1.1).
?For a variable of a reference-type, the default value is null.
C# LANGUAGE SPECIFICATION
102
[Note: Initialization to default values is typically done by having the
memory manager or garbage collector
initialize memory to all-bits-zero before it is allocated for use. For this
reason, it is convenient to use all-bitszero
to represent the null reference. end note]