Extended-precision floating-point (##)

Extended-precision floating-point numbers are the basis of computation in PowerBASIC. The type-specifier character for an Extended-precision floating-point is: ##. In PowerBASIC, all floating point calculations are performed in extended precision for maximum accuracy. Extended-precision has also been provided as a declarable variable type, so you can take advantage of its extra exponent range and precision.

Extended-precision variables require 10 bytes of storage each. They have a range of approximately +/- 3.4*10^-4932 to 1.2*10^4932, and offer 18 digits of precision. All 18 digits can be "displayed" using the extended STR$ format (eg, STR$(var##,18)).

Extended-precision variables are identified by adding two Number symbols following a variable name (i.e., var##) or by using the DEFEXT statement.. You can also declare Extended-precision variables using the EXT or EXTENDED keywords with the DIM statement. For example:

DIM I AS EXT
DIM J AS EXTENDED