Convert binary to
decimal
Can someone give me an idea of a
simple way to convert binary (base2) to
decimal(base10).
Solution 1
[Anatoly Podgoretsky, kvk@estpak.ee]
////////////////////////////////////////////////
// convert 32 bit base2 to 32 bit
base10 //
// max number = 99 999 999, return
-1 if more //
////////////////////////////////////////////////
function Base10(Base2:Integer) :
Integer; assembler;
asm
cmp eax,100000000 // check upper limit
jb @1 // ok
mov eax,-1 // error flag
jmp @exit // exit with -1
@1:
push ebx // save registers
push esi
xor esi,esi // result = 0
mov ebx,10 // diveder base 10
mov ecx,8 // 8 nibbles (10^8-1)
@2:
mov edx,0 // clear remainder
div ebx // eax DIV 10, edx mod
10
add esi,edx // result = result +
remainder[I]
ror esi,4 // shift nibble
loop @2 // loop for all 8 nibbles
mov eax,esi // function result
pop esi // restore registers
pop ebx
@exit:
end;
Solution 2
[Oliver Townshend, oliver@zip.com.au]
function IntToBin(Value:
LongInt;Size: Integer): String;
var
i:
Integer;
begin
Result:='';
for
i:=Size downto 0 do begin
if
Value and (1 shl i)<>0 then begin
Result:=Result+'1';
end
else begin
Result:=Result+'0';
end;
end;
end;
function BinToInt(Value: String):
LongInt;
var
i,Size:
Integer;
begin
Result:=0;
Size:=Length(Value);
for
i:=Size downto 0 do begin
if
Copy(Value,i,1)='1' then begin
Result:=Result+(1
shl i);
end;
end;
end;
Solution 3
[Demian Lessa, knowhow@compos.com.br]
Give this
function any decimal value, specify a base (1..16) and it will return you a
string containing the proper value, BaseX. You can use a similar method for
Arabic/Roman conversion (see below).
function DecToBase( Decimal:
LongInt; const Base: Byte): String;
const
Symbols: String[16] = '0123456789ABCDEF';
var
scratch: String;
remainder: Byte;
begin
scratch := '';
repeat
remainder := Decimal mod Base;
scratch := Symbols[remainder + 1] + scratch;
Decimal := Decimal div Base;
until ( Decimal = 0 );
Result := scratch;
end;
Give this
function any decimal value (1...3999), and it will return you a string
containing the proper value in Roman notation.
function DecToRoman( Decimal: LongInt
): String;
const
Romans: Array[1..13] of String =
( 'I', 'IV', 'V', 'IX', 'X', 'XL', 'L', 'XC', 'C', 'CD', 'D', 'CM', 'M'
);
Arabics: Array[1..13] of Integer =
( 1, 4, 5, 9, 10, 40, 50, 90, 100, 400, 500, 900, 1000);
var
i: Integer;
scratch: String;
begin
scratch := '';
for i := 13 downto 1 do
while ( Decimal >= Arabics[i] ) do
begin
Decimal := Decimal - Arabics[i];
scratch := scratch + Romans[i];
end;
Result := scratch;
end;