1、变量的定义
VAR
变量名：变量类型；
例：var
sex:string; (冒号与分号都是英文输入)
同类型的多个变量的定义
VAR
变量名1，变量名2，变量名3：变量类型；
例：var
sex,taste,grade:string;
2、变量的命名
（1）首字符必须是英文。
（2）只能由英文、数字和下划线组成。
例：制作单选按钮和复选按钮
unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls; type TForm1 = class(TForm) Label1: TLabel; Label2: TLabel; Label3: TLabel; RadioButton1: TRadioButton; RadioButton2: TRadioButton; GroupBox1: TGroupBox; CheckBox1: TCheckBox; CheckBox2: TCheckBox; CheckBox3: TCheckBox; CheckBox4: TCheckBox; CheckBox5: TCheckBox; CheckBox6: TCheckBox; RadioGroup1: TRadioGroup; Button1: TButton; Edit1: TEdit; procedure Button1Click(Sender: TObject); procedure RadioButton2Click(Sender: TObject); procedure CheckBox1Click(Sender: TObject); procedure RadioGroup1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; sex,taste,grade:string; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); begin showmessage(‘您的姓名是：‘+edit1.Text+#13#10+ ‘你的性别是：‘+sex+#13#10+ ‘你的爱好是：‘+taste+#13#10+ ‘你的成绩是：‘+grade ); end; procedure TForm1.RadioButton2Click(Sender: TObject); begin if radiobutton2.Checked then sex:=‘男‘ else if radiobutton1.Checked then sex:=‘女‘ ; end; procedure TForm1.CheckBox1Click(Sender: TObject); begin taste:=‘‘; if checkbox1.Checked then if taste=‘‘ then taste:=checkbox1.Caption else taste:=taste+‘、‘+checkbox1.Caption ; if checkbox2.Checked then if taste=‘‘ then taste:=checkbox2.Caption else taste:=taste+‘、‘+checkbox2.Caption ; if checkbox3.Checked then if taste=‘‘ then taste:=checkbox3.Caption else taste:=taste+‘、‘+checkbox3.Caption ; if checkbox4.Checked then if taste=‘‘ then taste:=checkbox4.Caption else taste:=taste+‘、‘+checkbox4.Caption ; if checkbox5.Checked then if taste=‘‘ then taste:=checkbox5.Caption else taste:=taste+‘、‘+checkbox5.Caption ; if checkbox6.Checked then if taste=‘‘ then taste:=checkbox6.Caption else taste:=taste+‘、‘+checkbox6.Caption ; end; procedure TForm1.RadioGroup1Click(Sender: TObject); begin case radiogroup1.ItemIndex of 0:grade:=‘优‘; 1:grade:=‘良‘; 2:grade:=‘中‘; 3:grade:=‘差‘; end; end; end.