interfaces only work on methods. https://play.golang.org/p/o6Ot4IdJZ1
Name, Age , ... are not methods they are fields.You need to make them part of Speaker interface by using methods instead of fields. Le mardi 22 novembre 2016 23:03:54 UTC+1, Tong Sun a écrit : > > > > On Tue, Nov 22, 2016 at 4:29 PM, Jesse McNelis wrote: > >> On Wed, Nov 23, 2016 at 8:16 AM, Tong Sun wrote: >> > Hi, >> > >> > How to architect the OO's virtual function in Go? >> > >> > Please take a look at this (not working) Go program >> > https://play.golang.org/p/qrBX6ScABp >> > >> > Please think of the "func Output()" as a very complicated function that >> I >> > only want to define once at the base level, not to duplicate into each >> sub >> > classes. >> > >> > How can I make it works so that the last output statement, instead of >> being, >> > >> > fmt.Printf("[%v] %s: [%0.2f]\n", k, v.Name(), v.Area()) >> > >> > >> > will be this instead: >> > >> > fmt.Printf("[%v] %s\n", k, v.Output()) >> > >> >> You define a function: >> >> func Output(s Shape) string { >> return s.Name() + "'s area size is " + s.Area() >> } >> >> Go uses interfaces for polymorphism. >> Other OOP languages can use inheritance for polymorphism too, but Go >> doesn't have inheritance. >> > > Thanks Jesse. That works. > > However I just realized that it is only part of my problem. > > I have a huge list of common variables that I defined in my "base class", > changing it from a member function to a pure function causes almost every > single variable now undefined. > > I can demonstrate the problem with this code > https://play.golang.org/p/QjCtD9rGpa > > So, once again, thinking in OO, I'll define all of the common variables in > base class, and common functionalities in virtual functions. How to make > that idea work in Go? > > For the above specific code, how to easily make "func Output" works? > > Thanks > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
