unit1.pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  yyzmj:set of Char;          //定义集合变量
  str:String;
  k,m:Integer;
begin
  yyzmj:=[];                  //给集合变量赋初值
  k:=Length(Edit1.Text);
  for m:=1 to k do
    begin
      str:=Copy(Edit1.Text,m,1);
      if str='a' then
            yyzmj:=yyzmj+['a']; //如有元音字母就给集合变量添加一个元素
      if str='e' then
              yyzmj:=yyzmj+['e'];
      if str='i' then
              yyzmj:=yyzmj+['i'];
      if str='o' then
             yyzmj:=yyzmj+['o'];
      if str='u' then
             yyzmj:=yyzmj+['u'];
    end;
  if yyzmj<>[] then          //根据集合变量是否为空集显示相关文本
    Edit2.Text:='有元音字母'
  else
    Edit2.Text:='没有元音字母';
end;


end.