Title: IntToHex Counterparts (HexToInt,IntToBin and BinToInt)
Question: Delphi kindly gave us IntToHex, but forgot to supply it's counterpart HexToInt. Also no binary functions are in the sysutils unit, IntToBin and BinToInt. Here's how to implement the missing functionality.
Uses Delphi 5 Int64 type but can be modified for all Delphi versions.
Answer:
{ ======================================= }
{ Convert a HexString value to an Int64 }
{ Note : Last Char can be 'H' for Hex }
{ eg. '00123h' or '00123H' }
{ 0 will be returned if invalid HexString }
{ ======================================= }
function HexToInt(HexStr : string) : Int64;
var RetVar : Int64;
i : byte;
begin
HexStr := UpperCase(HexStr);
if HexStr[length(HexStr)] = 'H' then
Delete(HexStr,length(HexStr),1);
RetVar := 0;
for i := 1 to length(HexStr) do begin
RetVar := RetVar shl 4;
if HexStr[i] in ['0'..'9'] then
RetVar := RetVar + (byte(HexStr[i]) - 48)
else
if HexStr[i] in ['A'..'F'] then
RetVar := RetVar + (byte(HexStr[i]) - 55)
else begin
Retvar := 0;
break;
end;
end;
Result := RetVar;
end;
{ ============================================== }
{ Convert an Int64 value to a binary string }
{ NumBits can be 64,32,16,8 to indicate the }
{ return value is to be Int64,DWord,Word }
{ or Byte respectively (default = 64) }
{ NumBits normally are only required for }
{ negative input values }
{ ============================================== }
function IntToBin(IValue : Int64; NumBits : word = 64) : string;
var RetVar : string;
i,ILen : byte;
begin
RetVar := '';
case NumBits of
32 : IValue := dword(IValue);
16 : IValue := word(IValue);
8 : IValue := byte(IValue);
end;
while IValue 0 do begin
Retvar := char(48 + (IValue and 1)) + RetVar;
IValue := IValue shr 1;
end;
if RetVar = '' then Retvar := '0';
Result := RetVar;
end;
{ ============================================== }
{ Convert a bit binary string to an Int64 value }
{ Note : Last Char can be 'B' for Binary }
{ eg. '001011b' or '001011B' }
{ 0 will be returned if invalid BinaryString }
{ ============================================== }
function BinToInt(BinStr : string) : Int64;
var i : byte;
RetVar : Int64;
begin
BinStr := UpperCase(BinStr);
if BinStr[length(BinStr)] = 'B' then Delete(BinStr,length(BinStr),1);
RetVar := 0;
for i := 1 to length(BinStr) do begin
if not (BinStr[i] in ['0','1']) then begin
RetVar := 0;
Break;
end;
RetVar := (RetVar shl 1) + (byte(BinStr[i]) and 1) ;
end;
Result := RetVar;
end;