Compare Protocol in Swift vs Interface in Java

Question

I\'m going through the iOS tutorial from Apple developer page.

It seems to me that protocol and interface almost have the same functionality.

Answer 1

Essentially protocols are very similar to Java interfaces except for:

• Swift protocols can also specify properties that must be implemented (i.e. fields)
• Swift protocols need to deal with value/reference through the use of the mutating keyword (because protocols can be implemented by structures, enumerations or classes).
• you can combine protocols at any point using "Protocol Composition". This replaces the older swift protocol way of protocol composition. For example, declaring a function parameter that must adhere to protocol Named and Aged as:

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

These are the immediately apparent differences for a Java developer (or at least what I've spotted so far). There's more info here.