Number
From TeamDeveloperWiki
This page covers Number datatype tips & tricks.
Contents |
How to combine two numbers to one and vice versa
To combine two numbers into one, use the next function
nCombined = VisNumberMakeLong( nValue1, nValue2)
You can find this function in vtmisc.apl
Beware that the two input parameters must have a value between 0 and 65535.
To get the two values back from the combined number
Set nValue1= SalNumberLow( nCombined ) Set nValue2= SalNumberHigh( nCombined )
How to convert a number to string using prefixed zeros
An easy way to do that is using this function
sResult = SalFmtFormatNumber( nValue, sPicture )
So if you want to have a string with 5 characters and if nValue results in less characters and should be prefixed with zeros
Set nValue = 12 Set sResult = SalFmtFormatNumber( nValue, "00000" ) ! Picture parameter has 5 zeros specified ! sResult has the value "00012"
An alternative way to define a number in boolean expressions
Look at the next piece of code
If bOk = TRUE
Set nValue = 1
Else
Set nValue = -1
It can be rewritten using one line of code using this function from vtmisc.apl
nResult = VisNumberChoose( bExpression, nTrueNumber, nFalseNumber )
So the If/Else construction above can be rewritten to
Set nValue = VisNumberChoose( bOk = TRUE, 1, -1 )
See also String : An alternative way to define a string in boolean expressions
How to convert from one base to another (eg decimal to hexadecimal to binary)
Developers familiar with the C(++) language will probably know conversion functions like itoa and strtol.
The itoa function (integer to ascii) is able to convert/format a decimal integer number to a given base (eg hexadecimal, binary, octal etc).
The function strtol does the opposite, converting a base to decimal.
These functions are also available to other programming languages with the MSCRT library (C runtime).
So also for TD.
First declare these external functions (below the declarations for TD versions prior to TD5.x) :
Library name: MSVCRT.dll
Function: _itoa
Export Ordinal: 0
Returns
Parameters
Number: INT
Receive String: LPSTR
Number: INT
Function: strtol
Export Ordinal: 0
Returns
Number: LONG
Parameters
String: LPCSTR
Number: LPVOID
Number: INT
Below the declarations for TD 5.x versions :
Library name: MSVCRT.dll
Function: _itow
Export Ordinal: 0
Returns
String: LPWSTR
Parameters
Number: INT
Receive String: LPWSTR
Number: INT
Function: wcstol
Export Ordinal: 0
Returns
Number: LONG
Parameters
String: LPCWSTR
Number: LPVOID
Number: INT
See more info concerning these CRT functions on MSDN :
_itoa, _i64toa, _ui64toa, _itow, _i64tow, _ui64tow
strtol, wcstol, _strtol_l, _wcstol_l
The next piece of code converts a decimal integer to the given base
Call SalStrSetBufferLength( sBuffer, 32 ) ! Set nToBase to 2..36 (2 = binary, 8 = octal, 10 = decimal, 16 = hexadecimal) Call _itoa( nDecimalNumber, sBuffer, nToBase ) ! sBuffer holds the converted decimal in the given base
Here the code to convert a base number to decimal
Set nNumber = strtol( sBaseValue, NUMBER_Null, nBase )
Examples
! Next, decimal to hexadecimal Call _itoa( 125, sBuffer, 16 ) ! sBuffer = "7d" ! Next, decimal to octal Call _itoa( 125, sBuffer, 8 ) ! sBuffer = "175" ! Next, decimal to binary Call _itoa( 125, sBuffer, 2) ! sBuffer = "1111101" ! ! Next, binary to decimal Set nNumber = strtol( "101, NUMBER_Null, 2 ) ! nNumber = 5
Using these functions you are able to convert from one base to another.
The sample can be downloaded below, it uses wrapper PAL functions for the CRT functions and a Base2Base function.
(Separate TD5.x sample provided)
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