unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls;type  TForm1 = class(TForm)    Button1: TButton;    Button2: TButton;    Button3: TButton;    Button4: TButton;    Button5: TButton;    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);    procedure Button4Click(Sender: TObject);    procedure Button5Click(Sender: TObject);  end;var  Form1: TForm1;implementation{$R *.dfm}{对字符}procedure TForm1.Button1Click(Sender: TObject);var  C: Char;begin  C := 'a';  C := Char(CharUpper(PChar(C)));  ShowMessage(C); {A}end;{对字符常量}procedure TForm1.Button2Click(Sender: TObject);var  C: Char;begin  C := Char(CharUpper(PChar('a')));  ShowMessage(C); {A}end;{对字符数组}procedure TForm1.Button3Click(Sender: TObject);var  Arr: array[0..2+1] of Char;begin  Arr := 'abc';  CharUpper(Arr);  ShowMessage(Arr); {ABC}end;{对字符串}procedure TForm1.Button4Click(Sender: TObject);var  str: string;begin  str := 'abc';  CharUpper(@str[1]);  ShowMessage(str); {ABC}end;{Delphi 的 System.UpCase 和 SysUtils.LowerCase}procedure TForm1.Button5Click(Sender: TObject);var  c: Char;  str: string;begin  c := 'a';  c := UpCase(c);  str := 'abc';  str := UpperCase(str);  ShowMessageFmt('%s, %s', [c, str]); {A, ABC}end;end.