Power of a Number in Delphi

Here is a sample program that I wrote in Delphi as my programming language that will ask the user to give the base and exponent value and then our program will compute the power of the number. I hope you will find my work useful I used the power function written by Jack Lyle in this program. The version of Delphi I used in this sample program is Delphi 4 Professional Edition.

Add me at Facebook my address is jakerpomperada@gmail.com and jakerpomperada@yahoo.com.

 
My mobile number here in the Philippines is 09173084360.

Sample Program Output

Program Listing

power.pas

unit power;

interface

uses

  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,

  StdCtrls;

type

  TForm1 = class(TForm)

    Label1: TLabel;

    Label2: TLabel;

    Edit1: TEdit;

    Label3: TLabel;

    Edit2: TEdit;

    Button1: TButton;

    Label4: TLabel;

    Button2: TButton;

    Label5: TLabel;

    Label6: TLabel;

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.DFM}

{** A power function from Jack Lyle. Said to be more powerful than the

    Pow function that comes with Delphi. }

function Power2(Base, Exponent : Double) : Double;

{ raises the base to the exponent }

  CONST

    cTiny = 1e-15;

  VAR

    Power : Double; { Value before sign correction }

  BEGIN

    Power := 0;

    { Deal with the near zero special cases }

    IF (Abs(Base) < cTiny) THEN BEGIN

      Base := 0.0;

    END; { IF }

    IF (Abs(Exponent) < cTiny) THEN BEGIN

      Exponent := 0.0;

    END; { IF }

    { Deal with the exactly zero cases }

    IF (Base = 0.0) THEN BEGIN

      Power := 0.0;

    END; { IF }

    IF (Exponent = 0.0) THEN BEGIN

      Power := 1.0;

    END; { IF }

    { Cover everything else }

    IF ((Base < 0) AND (Exponent < 0)) THEN

        Power := 1/Exp(-Exponent*Ln(-Base))

    ELSE IF ((Base < 0) AND (Exponent >= 0)) THEN

        Power := Exp(Exponent*Ln(-Base))

    ELSE IF ((Base > 0) AND (Exponent < 0)) THEN

        Power := 1/Exp(-Exponent*Ln(Base))

    ELSE IF ((Base > 0) AND (Exponent >= 0)) THEN

        Power := Exp(Exponent*Ln(Base));

    { Correct the sign }

    IF ((Base < 0) AND (Frac(Exponent/2.0) <> 0.0)) THEN

      Result := -Power

    ELSE

      Result := Power;

  END; { FUNCTION Pow }

var base,exponent: integer;

var solve : double;

procedure TForm1.Button1Click(Sender: TObject);

begin

   base      := strtoint(Edit1.Text);

   exponent  := strtoint(Edit2.Text);

   solve     :=   Power2(base,exponent);

  label4.caption := 'The result is ' + floattostr(solve)+'.';

end;

procedure TForm1.Button2Click(Sender: TObject);

begin

edit1.text     :='';

edit2.text     :='';

label4.caption := '';

edit1.setfocus;

end;

end.