Mirror

How to break strings into individual tokens (substrings) (Views: 8)


Problem/Question/Abstract:

How to break strings into individual tokens (substrings)

Answer:

The following (simple) functions helped me handling substrings:

function GetToken(aString, SepChar: string; TokenNum: Byte): string;

{Parameters:
aString: the complete string
SepChar: a single character used as separator between the substrings
TokenNum: the number of the substring you want
result: the substring or an empty string if the are less then 'TokenNum' substrings}

var
  Token: string;
  StrLen: Byte;
  TNum: Byte;
  TEnd: Byte;
begin
  StrLen := Length(aString);
  TNum := 1;
  TEnd := StrLen;
  while ((TNum <= TokenNum) and (TEnd <> 0)) do
  begin
    TEnd := Pos(SepChar, aString);
    if TEnd <> 0 then
    begin
      Token := Copy(aString, 1, TEnd - 1);
      Delete(aString, 1, TEnd);
      Inc(TNum);
    end
    else
    begin
      Token := aString;
    end;
  end;
  if TNum >= TokenNum then
  begin
    GetToken1 := Token;
  end
  else
  begin
    GetToken1 := '';
  end;
end;

function NumToken(aString, SepChar: string): Byte;

{Parameters:
aString: the complete string
SepChar: a single character used as separator between the substrings
result: the number of substrings}

var
  RChar: Char;
  StrLen: Byte;
  TNum: Byte;
  TEnd: Byte;
begin
  if SepChar = ' # ' then
  begin
    RChar := ' * '
  end
  else
  begin
    RChar := ' # '
  end;
  StrLen := Length(aString);
  TNum := 0;
  TEnd := StrLen;
  while TEnd <> 0 do
  begin
    Inc(TNum);
    TEnd := Pos(SepChar, aString);
    if TEnd <> 0 then
    begin
      aString[TEnd] := RChar;
    end;
  end;
  NumToken1 := TNum;
end;

<< Back to main page