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https://github.com/QB64-Phoenix-Edition/QB64pe.git
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6e01fc8dce
Added new _STRCMP and _STRICMP commands for quick string comparisons. Cleaned up QB64 to finish removing the QUI (quick user insert) code and folders. Altered UCASE and LCASE routines to be faster in some situations for us.
44 lines
2.1 KiB
Plaintext
44 lines
2.1 KiB
Plaintext
The '''CVL''' function converts 4 byte [[GET]] or [[MKL$]] [[STRING]] values to [[LONG]] numeric values.
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::::::''Syntax:'' CVL(''4-byte string'')
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* Numeric values read from a [[RANDOM]]-access or [[BINARY]] disk file must be converted from [[ASCII]] string characters back into numbers if they are to be arithmetically manipulated.
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* [[LONG]] Integer values can be from -2147483648 to 2147483647.
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* [[CVL]] converts a 4 byte string created by [[MKL$]] to a [[LONG]] integer numerical value.
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* [[CVI]] converts a 2-byte string created by [[MKI$]] to an [[INTEGER]] numerical value.
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* [[CVS]] converts a 4-byte string created by [[MKS$]] to a [[SINGLE]]-precision numerical value.
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* [[CVD]] converts an 8-byte string created by [[MKD$]] to a [[DOUBLE]]-precision numerical value.
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* CV functions can only be used to convert values from [[MK$]] string function values or data from [[BINARY]] files!
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''Example 1: 4 byte [[ASCII]] character strings show how CVL multipliers convert [[MKL$]] values into a 4 byte [[LONG]] value.
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{{CodeStart}} '' ''
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{{Cl|PRINT}} {{Cl|CVL}}({{Cl|CHR$}}(1) + {{Cl|STRING$}}(3, 0)) '{{Cl|ASC}}(CHR$(1)) * 1 = 1
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{{Cl|PRINT}} {{Cl|CVL}}({{Cl|CHR$}}(0) + {{Cl|CHR$}}(1) + {{Cl|STRING$}}(2, 0)) '{{Cl|ASC}}(CHR$(1)) * 256 = 256
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{{Cl|PRINT}} {{Cl|CVL}}({{Cl|STRING$}}(2, 0) + {{Cl|CHR$}}(1) + {{Cl|CHR$}}(0)) '{{Cl|ASC}}(CHR$(1)) * 256 * 256 = 65536
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{{Cl|PRINT}} {{Cl|CVL}}({{Cl|STRING$}}(3, 0) + {{Cl|CHR$}}(1)) '{{Cl|ASC}}(CHR$(1)) * 256 * 256 * 256 = 16777216 '' ''
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{{CodeEnd}}
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''Example 2:''
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{{CodeStart}} '' ''
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{{Cl|FIELD}} #1, 4 {{Cl|AS}} N$, 12 {{Cl|AS}} B$...
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{{Cl|GET}} #1
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Y& = {{Cl|CVL}}(N$) '' ''
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{{CodeEnd}}
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:''Explanation:'' Reads a field from file #1, and converts the first four bytes (N$) into a long integer value assigned to the variable Y&.
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:Since a long number can contain as many as ten ASCII characters (ten bytes), writing a file using [[MKL$]] conversion, and reading with the CVL conversion, as many as six bytes per number recorded are saved on the storage medium.
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''See also:''
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* [[MKL$]], [[MKI$]], [[MKS$]], [[MKD$]]
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* [[CVI]], [[CVS]], [[CVD]]
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* [[_CV]], [[_MK$]]
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* [[Bitmaps]]
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{{PageNavigation}} |