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What is the return type of interface?
If an interface is defined to be the return type of a method then instances of classes derived from that interface can be returned. The benefit of doing that is no different from returning objects of classes derived from a class.
Should you return interfaces?
Return the appropriate interface to hide implementation details. Your clients should only care about what your object offers, not how you implemented it.
Can we use interface as return type?
Yes, you can return an interface. In this example func is like factory method — it can return different objects!
How are go interfaces implemented?
To implement an interface in Go, we just need to implement all the methods in the interface. Here we implement geometry on rect s. The implementation for circle s. If a variable has an interface type, then we can call methods that are in the named interface.
What is an implicit class interface?
With implicit interface implementations, the members of the interface are public in the class. With explicit implementations, in the class the interface members are not declared as public members and cannot be directly accessed using an instance of the class, but a cast to the interface allows accessing the members.
Can you return an interface as a return type?
The benefit of doing that is no different from returning objects of classes derived from a class. Either way, we can specify the base class or interface as a return type and then return instances of classes derived from the base whether that base is a class or interface.
What’s the difference between a class and an interface?
They seem syntactically similar, both containing methods and variables, but they are different in many aspects. A class is a user-defined blueprint or prototype from which objects are created. It represents the set of properties or methods that are common to all objects of one type.
When to return an interface or concrete type?
Generally speaking, you may start with interfaces, and only move to put the concrete type as the return type if you find that you use the extra methods more frequently than expected. Well, if you return an interface, you retain more flexibility. You can change the implementation later to return a different concrete type.
Which is the implementation of an interface in Java?
An implementation of an interface is the realization of that interface. Realization is being implemented within the class. Just return an instance of the class (A or B) which realizes the return-type interface. The point of declaring an interface as the return type is not to actually return something with only an interface type.