CODEWITHSUNDEEP
swiftobjective-c
FeleMed
FeleMed

Reputation: 621

In Swift, do we "send a message" or "call method/function"?

Does Swift keep the the method lookup list when compiled or does it call a function in a specific memory location?

Regarding this

Upvotes: 3

Views: 1122

Answers (1)

Ahmad Baracat
Ahmad Baracat

Reputation: 480

I would recommend you have a look at the below links, especially the first one because it explains the concepts with examples from C++ and Objective-C, in order to have a better understanding of the difference between static, late and dynamic dispatch (for methods).

In a nutshell:

Static dispatch

The function and its implementation is determined at compile time and thus can’t fail at runtime (because the compiler will not continue the compilation process unless the binding is successful).

Late dispatch

The function is determined at compile time, but the actual implementation depends on the type of the object at runtime. Important for inheritance. The compiler will check if the the class or any of its parents have the function declared, but its up to the runtime to choose which implementation to use. The late binding can be implemented using virtual tables like in the case of C++.

Dynamic dispatch

The function is determined at runtime, which in the case of Objective-C can be called by name and thus can fail at runtime if the receiver (object) doesn't implement or inherit a method that can respond to a specified message.

References

Upvotes: 5

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