Floating numbers

Question

10 can be represents as 1010 in bits. How can we represent 10.5 in bits.

A data type is called as decimal, same time system of counting based on the number ten also called as decimal. What is the reason for that?

Vulpes · Answer

Floating point numbers (float and double) are stored in a different way to integers. The details are complex but the format is known as IEC 60559 and details of this can be found here: http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=57469 There are several ways to show what the individual bytes (and hence bits) of a float or double are. I can show you how to do this if you want though I doubt whether you'll find the details very useful. To understand the 'decimal' type it's necessary to review some history. In COM and VB4/5/6 programming there was an 8 byte data type known as Currency which (IIRC) was accurate to 4 d.p. This wasn't sufficiently accurate for many purposes and a 16 byte Decimal type was introduced as well (accurate to 28 d.p.) though only as one of the sub-types of the Variant type. The name was probably chosen for lack of a better one! When .NET came along it was decided to standardize on the Decimal type (decimal in C#) and the Currency type wasn't therefore brought across as one of the standard types (it should have been IMO but there we are).

Maha · Answer

Thank you for your explanation.