There may be occasions when you want to convert a decimal number into another format, such as binary, octal or hexadecimal. You may even want to convert a number in one of these other formats back into decimal. Uniface does not contain any standard functions to do this conversion, so you have to write your own routines.
This document describes the pair of routines which I wrote to perform this conversion. One converts from DECIMAL to BASEn, the other converts from BASEn to DECIMAL. For those of you who slept through your maths lessons I will translate:
The form which I use to test these routines looks like this:
The field labeled Decimal (input) is for the decimal number. You can then press one of the DEC to BIN/OCT/HEX/B36 buttons in order to convert that number into the chosen format. If you then press one of the BIN/OCT/HEX/B36 to DEC buttons this will convert that value back into decimal and place the result in the Decimal (output) field.
To convert from decimal into one of the other formats I use the following code:
call DEC_TO_STRING(decimal_input, base, output_string)
where BASE is 2, 8, 16 or 36 (as explained above). The proc which is called looks like this:
entry DEC_TO_STRING ; convert decimal number to baseN params numeric pi_Decimal : IN numeric pi_Base : IN string po_String : OUT endparams variables string lv_Charset numeric lv_Decimal numeric lv_Remainder string lv_Char endvariables if (pi_Base < 2) | (pi_Base > 36) | (pi_Base = 10) message "BASE must be in the range 2-9 or 11-36" return(-1) endif ; maximum character string is 36 characters lv_Charset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" ; strip off excess characters (anything above pi_Base) lv_Charset = lv_Charset[1,pi_Base] lv_Decimal = pi_Decimal ; move to work area repeat ; get remainder after dividing by BASE lv_Remainder = (lv_Decimal % pi_Base) lv_Remainder = lv_Remainder + 1 ; starts from 1, not zero lv_Char = lv_Charset[lv_Remainder:1] ; get CHAR from array po_String = "%%lv_Char%%po_String" ; add to output lv_Decimal = lv_Decimal - (lv_Remainder -1) lv_Decimal = lv_Decimal / pi_Base until (lv_Decimal < 1) return(0) end DEC_TO_STRING
To convert from one of the other formats back into decimal I use the following code:
call STRING_TO_DEC(input_string, base, decimal_output)
where BASE must correspond to the format of INPUT_STRING. The proc which is called looks like this:
entry STRING_TO_DEC ; convert baseN to decimal number
params
string pi_String : IN
numeric pi_Base : IN
numeric po_Decimal : OUT
endparams
variables
string lv_Charset
numeric lv_Base
string lv_String
numeric lv_Remainder
string lv_Char
endvariables
if (pi_Base < 2) | (pi_Base > 36) | (pi_Base = 10)
message "BASE must be in the range 2-9 or 11-36"
return(-1)
endif
; maximum character string is 36 characters
lv_Charset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
; strip off excess characters (anything above pi_Base)
lv_Charset = lv_Charset[1,pi_Base]
lv_String = pi_String ; move to work area
repeat
lv_Char = lv_String[1:1] ; extract leading character
lv_String = lv_String[2] ; drop leading character
scan lv_Charset, lv_Char ; get offset in Charset
if ($result < 1)
message "Illegal character (%%lv_Char) in INPUT string"
return(-1)
endif
lv_Remainder = $result -1 ; starts from zero, not 1
po_Decimal = po_Decimal * pi_Base
po_Decimal = po_Decimal + lv_Remainder
until (lv_String = "")
return(0)
end STRING_TO_DEC
As you can see the code in each of my routines is not too complex. Feel free to copy them and add them to your own application library.
Click here to download my sample code.
Tony Marston
1st June 2002
mailto:tony@tonymarston.net
mailto:TonyMarston@hotmail.com
http://www.tonymarston.net