swap 交换
EDIT1.TEXT:='1';EDIT2.TEXT:='2';
SWAP后应该是
EDIT1.TEXT:='2'
EDIT2.TEXT:='1'
根据给的源码结果总是
EDIT1.TEXT:='2'
EDIT2.TEXT:='2'
求解
源码如下 ：
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm1 = class(TForm)
Edit1: TEdit;
Edit2: TEdit;
Button1: TButton;
procedure Button1Click(Sender: TObject);
procedure Swap_fun(var str_a:String; str_b:String);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
var
str1: String;
str2: String;
temp: String;
begin
str1:= Edit1.Text;
str2:= Edit2.Text;
Swap_fun(str1, str2);
Edit1.Text:= str1;
Edit2.Text:= str2;
end;
procedure tform1.Swap_fun(var str_a:String;str_b:String);
var
temp:string;
begin
temp:= str_a;
str_a:= str_b;
str_b:= temp;
end;
end.
提问请发悬赏贴
暂时不给你答案，自己看下下面的知识点
支持一下！ 每二个参数引用前边没有加VAR，或这样写：Var str_a ,str_b:String
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