From QB64 Wiki
- Syntax: CVD(8-byte string)
- The 8 byte string value was created by MKD$ or PUT.
- Numeric values read from a RANDOM-access or BINARY file must be converted from ASCII string characters back into numbers if they are to be arithmetically manipulated.
- DOUBLE values can range up to 15 decimal point digits. Decimal point accuracy depends on whole value places taken.
- CVD converts an 8-byte string created by MKD$ to a DOUBLE-precision numerical value.
- CVS converts a 4-byte string created by MKS$ to a SINGLE-precision numerical value.
- CVI converts a 2-byte string created by MKI$ to an INTEGER numerical value.
- CVL converts a 4 byte string created by MKL$ to a LONG integer numerical value.
- CV functions can only be used to convert values from MK$ string function values or data from BINARY files!
- Explanation: Reads a field from file #1, and converts the first eight bytes (N$) into an double-precision number assigned to the variable Y#.
- Since a double-precision number can contain as many as 15 ASCII characters (fifteen bytes), writing a file using MKD$ conversion, and reading with the CVD conversion, as many as 7 bytes per number recorded are saved on the storage medium.