unit1.pas

Delphi函数参考大全的CD

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  s1,s2,s3 : string;
begin
  s1 := '10.1';
  ShowMessage('s1'+' 的平方根为:   '+ FloatToStr(Sqrt(StrToFloat(s1))));
  s2 := '25';
  ShowMessage('s2'+' 的平方根为:   '+ FloatToStr(Sqrt(StrToFloat(s2))));
  try
  s3 := '-10';
  ShowMessage('s3'+' 的平方根为:   '+ FloatToStr(Sqrt(StrToFloat(s3))));
  except
    showmessage('开平方不能为负数。');
  end;
end;

end.