delphi实现函数/过程

过程：没有返回值，在可视化时用到 在过程声明参数中添加要返回的值作为参数，

声明  定义： procedure lei(x:integer;var z:integer);   调用：lei(ljzhi,ljres);    Edit2.Text:=inttostr(ljres);

在控制台中，直接在声明时，调用 writeln();

注意函数有返回值，因此调用的函数可以作为表达式来用；

控制台实现：

program Project1;
{$APPTYPE CONSOLE}
uses SysUtils;
procedure sum(x:integer;y:integer);
var z:integer;
begin
    z:=x+y;
    writeln('结果是:',z);
end;
function res(x:integer):integer;
begin
   result:=x+1 ;
end;
begin
  { TODO -oUser -cConsole Main : Insert code here }
   sum(3,4);
   writeln(res(5));
   readln;
end.

可视化实现：

unit leijia;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
implementation
{$R *.dfm}
procedure lei(x:integer;var z:integer);
var i:integer;
begin
  z:=0;
  for i:=0 to x do
  z:=z+i;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
  ljres,ljzhi:integer;
begin
ljzhi:=strtoint(Edit1.Text);
lei(ljzhi,ljres);
Edit2.Text:=inttostr(ljres);
end;
function cheng(x:integer):integer;
var i,j:integer;
begin
result:=1;
for i:=1 to x do
  result:=result*i;
end;
procedure TForm1.Button2Click(Sender: TObject);
var lczhi:integer;
begin
lczhi:=strtoint(Edit1.Text);
Edit2.Text:=inttostr(cheng(lczhi));
end;
end.