[bb] hex2dec by Blu_Matt [ 1+ years ago ]

[BlitzBot]

Title : hex2dec
Author : Blu_Matt
Posted : 1+ years ago

Description : The hexidecimal number can be in the Blitz format "$ffff" or just vanilla "FFFF" format.  The function is case-insensitive.

Code :

Code (blitzbasic) Select Expand

Function hex2dec%(hex_number$)
; Converts the supplied hex number into a decimal number
; If hex_number isn't a valid hex number, then returns -1
; written by Matt Burns (Blu_Matt / matt@blis.co.uk)
Local the_hex$=Upper(Trim(hex_number$)) ; the hex number
Local base_power%=0 ; the current base power
Local base%=16 ; the base to convert from
Local the_dec%=0 ; the decimal representation
Local chars%=0
Local hex_length%=Len(the_hex$) ; current length of the hex
If Left(the_hex$,1)="$" Then ; removes any leading "$"
the_hex$=Right(the_hex$,hex_length%-1)
EndIf
hex_length%=Len(the_hex$) ; current length of the hex
Local chars_left%=hex_length% ; current number of chars left
Local hex_left$=the_hex$ ; current hex left
Repeat
current_hex$=Right(hex_left$,1) ; gets the current hex char
If ((Asc(current_hex$)>=Asc("0")) And (Asc(current_hex$)<=Asc("9"))) Then
hex_dec%=current_hex$ ; digit 0-9
ElseIf ((Asc(current_hex$)>=Asc("A")) And (Asc(current_hex$)<=Asc("F"))) Then
hex_dec%=Asc(current_hex$)-55 ; char A-F
Else
Return -1 ; found an illegal character, aborting...
EndIf
the_dec%=the_dec%+((base%^base_power%)*hex_dec%) ; add the local hex digit to the total
base_power%=base_power%+1 ; increase the base power
chars_left%=chars_left%-1 ; reduce the number of chars left
hex_left$=Left(hex_left$,chars_left%) ; sets the remainder
Until chars_left%=0
Return the_dec% ; return the result
End Function

; testing, 1, 2, 3...
Print hex2dec("$ff") ; = 255
Print hex2dec("100") ; = 256

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