How to define optional methods in Swift protocol?

How to define optional methods in Swift protocol?

ios swift optional-parameters swift-protocols swift-extensions

ios

Usage of protocols as array types and function parameters in swift

ios swift generics swift-protocols

ios

In Swift, how can I declare a variable of a specific type that conforms to one or more protocols?

ios objective-c swift swift-protocols

ios

"fatal error: array cannot be bridged from Objective-C"—Why are you even trying, Swift?

ios swift swift-protocols

ios

Why I can't use let in protocol in Swift?

ios swift protocols getter-setter swift-protocols

ios

Swift extension of a class ONLY when it conforms to a specific protocol

ios swift uiviewcontroller swift-protocols swift-extensions

ios

IBOutlet crashing with EXC_BAD_ACCESS even though not nil

ios swift uiviewcontroller exc-bad-access swift-protocols

ios