Convert binary to decimal

Can someone give me an idea of a simple way to convert binary (base2) to decimal(base10).

Solution 1

////////////////////////////////////////////////

// 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

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;

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;

Solution 3

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;