swift3.0 extensions, protocols (4)

Extensions and protocols are two features in Swift that are used to extend and modify existing types.

Extension (extension)

Add new Features (properties, methods, subscript scripts, and so on) to existing types, extensions using the extension keyword definition, syntax

Extension classname{    //define properties, methods, etc.
    ...        }

Protocol (Protocol)

Used to declare the methods and properties necessary to complete the functionality of a task, or to be understood as a rule that accomplishes a task, whose syntax

protocol proname{     // Properties, Methods     ...  }

swift3.0 extensions, protocols (4)