interface

问题 This question already has answers here : How to make a Java class that implements one interface with two generic types? (9 answers) Closed 6 years ago . I have the following interface, which I want to implement multiple times in my classes: public interface EventListener<T extends Event> { public void onEvent(T event); } Now, I want to be able to implement this interface in the following way: class Foo implements EventListener<LoginEvent>, EventListener<LogoutEvent> { @Override public void

问题 This question already has answers here : How to make a Java class that implements one interface with two generic types? (9 answers) Closed 6 years ago . I have the following interface, which I want to implement multiple times in my classes: public interface EventListener<T extends Event> { public void onEvent(T event); } Now, I want to be able to implement this interface in the following way: class Foo implements EventListener<LoginEvent>, EventListener<LogoutEvent> { @Override public void

问题 This question already has answers here : How to make a Java class that implements one interface with two generic types? (9 answers) Closed 6 years ago . I have the following interface, which I want to implement multiple times in my classes: public interface EventListener<T extends Event> { public void onEvent(T event); } Now, I want to be able to implement this interface in the following way: class Foo implements EventListener<LoginEvent>, EventListener<LogoutEvent> { @Override public void

问题 I have an abstract class that declares const and non-const member functions. For the sake of discussion let's say it looks like this: class record_interface { public: virtual ~record_interface() = default; virtual void set_foo(BoundedFloat) = 0; virtual BoundedFloat get_foo() const = 0; }; This is used as a high-level representation of a record that has different representations when saved to disc and transferred via the wire. So most implementations just need to convert their members to the

问题 I am having difficulty understanding how to correctly unmarshal some JSON data that goes in to an array of type inteface and then use it. I tried to make this example code as simple as possible to illustrate the problem I am having. The code can be found in the playground here: https://play.golang.org/p/U85J_lBJ7Zr The output looks like: [map[ObjectType:chair ID:1234 Brand:Blue Inc.] map[ID:5678 Location:Kitchen ObjectType:table]] { } false { } false Code package main import ( "fmt" "encoding

问题 There are two type of statements on internet about Interface , that is Statement A Interfaces do not come in inheriting chain. other statement B Interfaces can inherit other interfaces These two are contradicting statements. Please tell me which one is right? 回答1: They are both true, sort of. Statement A: Interfaces don't strictly inherit. If you have a class that implements an interface, and you say base. You won't see members of the interface. Statement B: This would read better as

问题 I've recently taken a liking to the Go programming language, I've found it wonderful so far but am really struggling to understand interfaces. I've read about quite a bit about them, but they still seem very abstract to me. I've wrote a quick bit of code that uses an interface below: package main import ( "fmt" "math" ) type Circer interface { Circ() float64 } type Square struct { side float64 } type Circle struct { diam, rad float64 } func (s *Square) Circ() float64 { return s.side * 4 }

问题 I'm struggling with interfaces. Consider this: type Generatorer interface { getValue() // which type should I put here ? } type StringGenerator struct { length int } type IntGenerator struct { min int max int } func (g StringGenerator) getValue() string { return "randomString" } func (g IntGenerator) getValue() int { return 1 } I want the getValue() function to return a string or an int , depending on if it's called from StringGenerator or IntGenerator When I try to compile this, I get

问题 I'm struggling with interfaces. Consider this: type Generatorer interface { getValue() // which type should I put here ? } type StringGenerator struct { length int } type IntGenerator struct { min int max int } func (g StringGenerator) getValue() string { return "randomString" } func (g IntGenerator) getValue() int { return 1 } I want the getValue() function to return a string or an int , depending on if it's called from StringGenerator or IntGenerator When I try to compile this, I get

问题 I'm having trouble writing the generic interface below. In my class, I have a function that takes an array of < any type that extends a parent class > and traces its first element. Since I'm only reading elements from the array, I'm using it as if its a covariant compound type, and therefore I'm guaranteed to have the cast statement never fail. Now I want to abstract this out even more and write a interface that defines fn using another generic type T. I want fn to be able to accept any Array