Double variable range

[tiredofit]

A Double is defined to be in the range:

-1.79769313486231E308 to -4.94065645841247E324

and

4.94065645841247E-324 to 1.79769313486232E308

Why not just say,

-1.79769313486231E308 to 1.79769313486232E308

ie going from a large negative number, approaches zero, "through" zero, then to a large positive number?

Thanks

 

[Eric W]

You're missing some minus signs. The documentation says:

Holds signed IEEE 64-bit (8-byte) double-precision floating-point numbers that range in value from -1.79769313486231570E+308 through -4.94065645841246544E-324 for negative values and from 4.94065645841246544E-324 through 1.79769313486231570E+308 for positive values. Double-precision numbers store an approximation of a real number.

They're trying to show the extreme magnitudes that are possible, both in the large and small dimensions. The Double does NOT hold every possible number between -1.79769313486231570E+308 and 1.79769313486231570E+308. For example, 9.0E-400 or -9.0E-400 is an extremely tiny number between -1.79769313486231570E+308 and 1.79769313486231570E+308, but cannot be represented in a Double due to the -400 exponent.