SysUtils.StrLen Function

Returns number of characters in a string excluding the null terminator.

Pascal

function StrLen(const Str: PAnsiChar): Cardinal; overload;
function StrLen(const Str: PWideChar): Cardinal; overload;

C++

unsigned StrLen(const PAnsiChar Str);
unsigned StrLen(const PWideChar Str);

File

SysUtils

Description

StrLen returns the number of characters in Str, not counting the null terminator.

C++ Examples:

Copy Code

/*
The following example uses an edit control and a button on a
form in an application. When the button is clicked, the edit
control’s text is split in halves that are copied into
separate buffers. Then the contents of the buffers are
displayed in a message box.
*/
void __fastcall TForm1::Button1Click(TObject *Sender)
{
  AnsiString EditText = AnsiString(Edit1->Text);
  char* szFirstHalf = new char[StrLen(EditText.c_str())/2+2];
  char* szSecondHalf = new char[StrLen(EditText.c_str())/2+2];
  char* pszSecondHalf = &EditText[StrLen(EditText.c_str())/2+1];

  *szFirstHalf = 0;
  *szSecondHalf = 0;

  StrLCat(szFirstHalf, EditText.c_str(), StrLen(EditText.c_str())/2);
  StrCat(szSecondHalf, pszSecondHalf);

  Application->MessageBox(WideString(szFirstHalf).c_bstr(), L"First Half", MB_OKCANCEL);
  Application->MessageBox(WideString(szSecondHalf).c_bstr(), L"Second Half", MB_OKCANCEL);

  delete [] szFirstHalf;
  delete [] szSecondHalf;
}

Delphi Examples:

Copy Code

{
The following example uses an edit control and a button on a
form in an application. When the button is clicked, the edit
control’s text is split in halves that are copied into
separate buffers. Then the contents of the buffers are
displayed in a message box.
}
procedure TForm1.Button1Click(Sender: TObject);
var
  FirstHalf: PChar;
  SecondHalf: PChar;
  HalfLen: Integer;
begin
  HalfLen := StrLen(PChar(string(Edit1.Text))) div 2;
  GetMem(FirstHalf,HalfLen+2);
  GetMem(SecondHalf,HalfLen+2);
  FirstHalf^ := Chr(0);
  SecondHalf^ := Chr(0);
  StrLCat(FirstHalf, PChar(string(Edit1.Text)), HalfLen);
  StrCat(SecondHalf, PChar(string(Edit1.Text)) + HalfLen);
//  Application.MessageBox(FirstHalf, 'First Half', [smbOK], smsInformation, smbOK, smbCancel);
  Application.MessageBox(FirstHalf, 'First Half', MB_OKCANCEL);
  Application.MessageBox(SecondHalf, 'Second Half', MB_OKCANCEL);
  FreeMem(FirstHalf);
  FreeMem(SecondHalf);
end;