Protocols-vs-ClassDefaults.swift

protocol MyProtocol {
    func methodA()
    func methodB()
}

class MyProtocolDefaults {
    func methodA() {
        print("Default methodA")
    }
    
    func methodB() {
        methodA()
    }
}

// Test 1
class BaseClass: MyProtocolDefaults, MyProtocol {
    
}

class SubClass: BaseClass {
    override func methodA() {
        print("SubClass methodA")
    }
}


let object1 = SubClass()
object1.methodB()
//

// Test 2
class JustClass: MyProtocolDefaults, MyProtocol {
    override func methodA() {
        print("JustClass methodA")
    }
}

let object2 = JustClass()
object2.methodB()
//
// Output
// SubClass methodA
// JustClass methodA