BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Syntax question          BorlandTalk.com Forum Index -> Delphi OO design View previous topic :: View next topic   Author Message Wouter Devos [XLent Solut Guest Posted: Thu Nov 20, 2003 9:50 am    Post subject: Syntax question Hi, I have some syntax problem which is not clear to me. The interface section of the unit is like TDetailController = class (TXLSFormController) protected ....... procedure mGridPageDown (aObject: TObject); virtual; ........ public ........ end; In the implementation section, due to a 'mistake' i had procedure TDetailController.mGridPageDown; begin if Assigned (aObject) and (aObject is TcxGridDBTableView) then TXLSGridTableController(TcxGridDBTableView(aObject).Controller).FocusNextPag e(True); end; This compiles and runs fine. When renaming aObject to aaObject in the implementation section, I get an error (looks normal). When renaming aObject to aaObject in the interface and implemenation section it runs fine again. It looks like there is no need to specify the arguments here in the implementation section. Why does the compiler don't complain about the differences? Anyone can explain this? Regards, Wouter Devos Back to top Gert Kello Guest Posted: Thu Nov 20, 2003 10:29 am    Post subject: Re: Syntax question Quote: It looks like there is no need to specify the arguments here in the implementation section. Why does the compiler don't complain about the differences? AFAIK, it is the allowed pascal language syntax: the procedure/function/method declaration in implementation may omit the paramteres declaration. If it is present, it must be exactly same as in interface part. from Delphi help, "implementation section", the end of the first paragraph: "You can omit parameter lists from public procedure and function headings when you define them in the implementation section; but if you include a parameter list, it must match the declaration in the interface section exactly." -- Gert Back to top Jim Cooper Guest Posted: Thu Nov 20, 2003 11:09 am    Post subject: Re: Syntax question Quote: AFAIK, it is the allowed pascal language syntax: the procedure/function/method declaration in implementation may omit the paramteres declaration. If it is present, it must be exactly same as in interface part. And you need to declare the parameters on overloaded methods too, if that is the only difference in their signatures. Cheers, Jim Cooper ____________________________________________ Jim Cooper [email]jcooper (AT) tabdee (DOT) ltd.uk[/email] Tabdee Ltd http://www.tabdee.ltd.uk TurboSync - Connecting Delphi with your Palm ____________________________________________ Back to top Andrew Denton Guest Posted: Thu Nov 20, 2003 11:26 am    Post subject: Re: Syntax question Gert Kello wrote: Quote: It looks like there is no need to specify the arguments here in the implementation section. Why does the compiler don't complain about the differences? AFAIK, it is the allowed pascal language syntax: the procedure/function/method declaration in implementation may omit the paramteres declaration. If it is present, it must be exactly same as in interface part. from Delphi help, "implementation section", the end of the first paragraph: "You can omit parameter lists from public procedure and function headings when you define them in the implementation section; but if you include a parameter list, it must match the declaration in the interface section exactly." That is correct. All the Pascal implementations I have ever worked with (Macinstosh, USCD P-System, Turbo 3.0 onwards) have allowed you to exclude the parameterlist of a function/procedure. I always included them though as you end up having to page up/down between implementation and interface sections (this was before the days of CTRL+Up/Down Arrow). -- Cheers, Andy "I want to move to Theory....Everything works in Theory" Back to top Wouter Devos [XLent Solut Guest Posted: Thu Nov 20, 2003 1:44 pm    Post subject: Re: Syntax question Thanks all, I was not aware of this 'feature'. They never told me about it, and I'm definitely not going to use it. I found it very confusing and hard to read. But now I know it is correct. Regards, Wouter Devos "Andrew Denton" <adenton.diespamdie (AT) q-range (DOT) com> schreef in bericht news:3fbcb2f2 (AT) newsgroups (DOT) borland.com... Quote: Gert Kello wrote: It looks like there is no need to specify the arguments here in the implementation section. Why does the compiler don't complain about the differences? AFAIK, it is the allowed pascal language syntax: the procedure/function/method declaration in implementation may omit the paramteres declaration. If it is present, it must be exactly same as in interface part. from Delphi help, "implementation section", the end of the first paragraph: "You can omit parameter lists from public procedure and function headings when you define them in the implementation section; but if you include a parameter list, it must match the declaration in the interface section exactly." That is correct. All the Pascal implementations I have ever worked with (Macinstosh, USCD P-System, Turbo 3.0 onwards) have allowed you to exclude the parameterlist of a function/procedure. I always included them though as you end up having to page up/down between implementation and interface sections (this was before the days of CTRL+Up/Down Arrow). -- Cheers, Andy "I want to move to Theory....Everything works in Theory" Back to top Marc Rohloff Guest Posted: Thu Nov 20, 2003 2:29 pm    Post subject: Re: Syntax question On Thu, 20 Nov 2003 11:09:03 +0000, Jim Cooper<jcooper (AT) tabdee (DOT) ltd.uk> said ... Quote: And you need to declare the parameters on overloaded methods too, if that is the only difference in their signatures. How else can overloaded methods be different apart from their parameters? Marc Back to top Jim Cooper Guest Posted: Thu Nov 20, 2003 10:03 pm    Post subject: Re: Syntax question Quote: How else can overloaded methods be different apart from their parameters? Return types. Cheers, Jim Cooper ____________________________________________ Jim Cooper [email]jcooper (AT) tabdee (DOT) ltd.uk[/email] Tabdee Ltd http://www.tabdee.ltd.uk TurboSync - Connecting Delphi with your Palm ____________________________________________ Back to top Marc Rohloff Guest Posted: Thu Nov 20, 2003 10:18 pm    Post subject: Re: Syntax question In article <3FBD3A42.1ECFE543 (AT) tabdee (DOT) ltd.uk>, [email]jcooper (AT) tabdee (DOT) ltd.uk[/email] says... Quote: How else can overloaded methods be different apart from their parameters? Return types. Functions must differ by more than just their return types. The following gives a compile error: function func(a,b:integer):integer; overload; function func(a,b:integer):double; overload; Marc Back to top Jim Cooper Guest Posted: Fri Nov 21, 2003 12:55 am    Post subject: Re: Syntax question Quote: Functions must differ by more than just their return types. You are correct. I had thought different return types was sufficient, but they have to be different parameter signatures as well. Cheers, Jim Cooper ____________________________________________ Jim Cooper [email]jcooper (AT) tabdee (DOT) ltd.uk[/email] Tabdee Ltd http://www.tabdee.ltd.uk TurboSync - Connecting Delphi with your Palm ____________________________________________ Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> Delphi OO design All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.