// assigning an unsigned short to its minimum value
ushort s = 0;

// assigning an unsigned short to its maximum value
ushort s = 65535;

// assigning an unsigned int to its minimum value
uint i = 0;

// assigning an unsigned int to its maximum value
uint i = 4294967295;

// assigning an unsigned long to its minimum value (note the unsigned long postfix)
ulong l = 0UL;

// assigning an unsigned long to its maximum value (note the unsigned long postfix)
ulong l = 18446744073709551615UL;

It is also possible to make these types nullable, meaning that additionally to the usual values, null can be assigned, too. If a variable of a nullable type is not initialized, it will be null instead of 0. Nullable types are marked by adding a question mark (?) after the type.

uint a;  // This is now 0.
uint? b; // This is now null.