There are very few absolutes in life; however, I’m about to give you a C#
absolute: Every expression has a value and a type. In a declaration such as
int n, you can easily see that the variable n is an int. Further, you can reasonably
assume that the type of a calculation n + 1 is an int. However, what
type is the constant 1?
The type of a constant depends on two things: its value and the presence of an
optional descriptor letter at the end of the constant. Any integer type less than
2 billion is assumed to be an int. Numbers larger than 2 billion are assumed to
be long. Any floating pointing number is assumed to be a double.
Table 3-4 demonstrates constants that have been declared to be of a particular
type. The case of these descriptors is not important. Thus, 1U and 1u are
equivalent.