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iOS

Posted by Mitch Little
Mitch Little
11,870 Points

Protocol Inheritance Vs Protocol Composition

Just trying to define the difference between protocol inheritance and protocol composition.

As far as I know

Protocol Inheritance is when protocols inherit from other protocols such as:

protocol Dog: Animal, Mammal {
    // requirements
}

Protocol Composition is when objects conform and are 'composed' of multiple protocols such as:

struct Example: ProtocolExampleOne, ProtocolExampleTwo {
    // Protocol Requirements
}

Also, when composition is involved in a function type, the protocols are separate with '&'. For example:

func wishHappyBirthday(to celebrator: Named & Aged) {}

Is my knowledge all correct here?

Any help would be greatly appreciated as I slightly confused myself earlier.

Thank you,

Mitch

1 Answer

Mitch Little
Mitch Little
11,870 Points

Yes I have thank you Jeff, my first point of call!

But after reading I was just confirming I had it correct in my understanding.