unit1.pas

这有很多Delphi应用的例子

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Edit1: TEdit;
    Label5: TLabel;
    Button1: TButton;
    Label6: TLabel;
    Label7: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
type
  Tvowels=set of Char;
var
  Vowels,HalfVowels:TVowels;
begin
  Vowels := ['a','e','i','o','u','A','E','I','O','U'];
  HalfVowels := ['y','Y'];
  if Edit1.Text[1] in Vowels
     then Label5.Caption := '是元音'
     else if Edit1.Text[1] in HalfVowels
             then Label5.Caption := '是半元音'
             else Label5.Caption := '是辅音';
end;


end.