CVD: Difference between revisions
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* [https://qb64phoenix.com/forum/showthread.php?tid=1066 Featured in our "Keyword of the Day" series] | |||
* [[MKD$]], [[MKI$]], [[MKS$]], [[MKL$]], [[MKDMBF$]], [[MKSMBF$]] | * [[MKD$]], [[MKI$]], [[MKS$]], [[MKL$]], [[MKDMBF$]], [[MKSMBF$]] | ||
* [[CVI]], [[CVS]], [[CVL]], [[CVSMBF]], [[CVDMBF]] | * [[CVI]], [[CVS]], [[CVL]], [[CVSMBF]], [[CVDMBF]] |
Latest revision as of 19:27, 24 May 2024
The CVD function decodes an 8-byte STRING generated by MKD$ (or read from a file) to DOUBLE numeric values.
Syntax
- result# = CVD(stringData$)
Description
- CV functions (CVD, CVS, CVI, CVL, CVDMBF, CVSMBF) are used to convert values encoded by MK$ functions (MKD$, MKS$, MKI$, MKL$, MKDMBF$, MKSMBF$).
- Variables of numerical types are also encoded when PUT to a RANDOM or BINARY-access file.
- QB64 has _CV and _MK$ functions which can also deal with extended data types.
- DOUBLE values can range up to 15 decimal point digits. Decimal point accuracy depends on whole value places taken.
Examples
Example 1: Reading an 8-byte encoded string n$ from a file and obtaining the decoded DOUBLE value:
FIELD #1, 8 AS N$, 12 AS B$... GET #1 Y# = CVD(N$) |
- Explanation: Reads a field from file #1, and converts the first eight bytes (N$) into an double-precision number assigned to the variable Y#.
Example 2: Showcases the reduced space to store an encoded number.
a# = 77000.24523213 PRINT "Value of a#:"; a# b$ = MKD$(a#) PRINT "Value of a# encoded using MKD$: "; b$ PRINT "The string above, decoded using CVD:"; CVD(b$) |
Value of a#: 77000.24523213 Value of a# encoded using MKD$: ñåxýâ╠‗@ The string above, decoded using CVD: 77000.24523213 |
- Since the representation of a double-precision number can use up to 15 ASCII characters (fifteen bytes), writing to a file using MKD$ conversion, and then reading back with the CVD conversion can save up to 7 bytes of storage space.
See also
See also
- Featured in our "Keyword of the Day" series
- MKD$, MKI$, MKS$, MKL$, MKDMBF$, MKSMBF$
- CVI, CVS, CVL, CVSMBF, CVDMBF
- _CV, _MK$