floating_point_type

Objects of floating_point_type may take on values representing non-integer, rational, numbers. Internally these are represented in so called floating point format. This is somewhat like normal scientific notation - such as . That is, there is a mantissa ( in this example) and a separate exponent ( in this example). The mantissa has a some finite range which, in effect, determines the number of significant digits that can be represented. The exponent also has a finite range which determines the maximum and minimum absolute values which can be represented. Of course, internally in the computer, both the mantissa and the exponent are represented in binary notation; and the exponent is a power of 2 (normally) rather than a power of 10.

In the particular case of floating_point_type, the mantissa is equivalent to approximately 15 decimal digits; and the exponent is equivalent to approximately .

Constants of floating_point_type may be represented in your programs in normal decimal notation, except that the decimal point must be present, even if the fractional part is intended as zero. Thus, 3.414 is a perfectly good floating_point_type value, whereas 24 is not - it would be interpreted as an integer_type value. If you mean the floating_point_type value corresponding to the number 24, then code it as 24.0 instead. Very large or small floating_point_type constants can be represented using scientific notation like this: -23.86e54 (for ) or 0.7433681e-123 (for ).