In an article on MSDN, it states that the double data type has a range of \"-1.79769313486232e308 .. 1.79769313486232e308\". Whereas the long data
double
long
long is a signed 64-bit integer value and double is a 64-bit floating point value. Looking at their FCL types might make more sense. long maps to System.Int64 and double maps to System.Double.
System.Int64
System.Double