Delphi String Case Conversion - Sentence Case, Title Case, Toggle

Delphi String Case Conversion functions for Title Case, Sentence case or toggle the case (convert upper to lower, lower to upper case)

function SentenceCase(Text2:string):string;
var i:integer;
    t: string;
begin
   for i:=2 to Length(Text2) do
   begin
     if (Text2[i-1] in ['.','!','?']) then
     begin
       Text2[i]:=UpCase(Text2[i]);
     end
     else
     begin
       t := LowerCase(Text2[i]);
       Text2[i]:=t[1];
     end;
   end;
   Result:=Text2;
end;

function ToggleCase(Text2:string):string;
var i:integer;
    t: string;
begin
   for i:=2 to length(Text2) do
   begin
     if (Text2[i] in ['A'..'Z']) then
     begin
       t := LowerCase(Text2[i]);
       Text2[i]:= t[1];
     end
     else
     if (Text2[i] in ['a'..'z']) then
     begin
       Text2[i]:=UpCase(Text2[i])
     end;
   end;
   Result:=Text2;
end;

function TitleCase(Text2:string):string;
var i:integer;
    t: string;
begin
   for i:=2 to length(Text2) do
   begin
     if (not(Text2[i-1] in ['A'..'Z','a'..'z'])) then
      Text2[i]:=UpCase(Text2[i])
     else
     begin
       t := LowerCase(Text2[i]);
       Text2[i] := t[1];
     end;
   end;
   Result:=Text2;
end;