Mega Code Archive
Display a value in a different base like hex or binary
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Title: Display a value in a different base like hex or binary.
Question: Sometimes, you need to change the base system of a decimal number, foer example you want to display a decimal number x to its hexadecimal equilivant, or octal, or binary! Or even switch between hexadecimal and binary! This article describes an standard way how to do this and encapsulates the whole in a component where you can change the in- and outbase from 2 to 36.
Answer:
In Delphi, you can only calculate in a decimal system or hexadecimal. But there is no way to change to another system. Therefore, you already need 2 functions:
1. One to transform a decimal number to another basesystem. I will name this function _10ToB
2. And one to tranform a number from any system to decimal. This will be the function _Bto10
With these 2 functions, you will be able to switch from any base system to another, by the midway of first tranforming the number in a decimal format (_Bto10), and then to the desired base system (_10toB).
Here are the 2 functions in detail. An array of char (Trans) is needed to make a display possible:
const
Trans : array[0..35] of char = ('0','1','2','3','4','5','6','7','8','9',
'A','B','C','D','E','F','G','H','I','J',
'K','L','M','N','O','P','Q','R','S','T',
'U','V','W','X','Y','Z') ;
function _10ToB (ID : integer;
b : integer) : string ;
begin
Result := '' ;
while ID 0
do begin
Result := Trans[ID mod b] + Result ;
ID := ID div b ;
end ;
if Result = '' then
Result := '0';
end;
function _BTo10 (BC : string ;
b : integer ) : integer ;
var
x : char ;
i, k, L : integer ;
Found : boolean ;
begin
Result := 0 ;
Invalid := false ;
L := Length(BC) ;
for i := 0 to L-1
do begin
x := BC[L-i] ;
k := 0 ;
Found := false ;
repeat
if x = Trans[k] then found := true
else k := k + 1 ;
until (k b-1) or Found ;
if found
then Result := Result + k*Pow(b,i) { Pow is a function that calculates b^i }
else begin
Invalid := true ;
Result := 0 ;
Exit ;
end ;
end ;
end;
I have included the whole thing in a component that you may download from
http://www.rhrk.uni-kl.de/~peiffer/downloads/BaseSwitcher.zip
Tom Peiffer
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