Extensions and Protocols

1. Extension: Swift uses an extension mechanism that can be used in the original class struct and enumeration, in the following format:

Extension type name {

New features

}

New features can be added in the original type (class, struct, enum) including: 1, instance computed properties and static computed properties 2, instance method and static method 3, constructor 4, subscript.

2, protocol: All methods are abstract, called Protocol (Protocol) similar to the C # interface. The protocol is highly abstract, and he has only abstract method names, parameter lists, and return values. Implementations become compliance protocols that implement both interfaces.

Declaration Agreement:

Protocol protocol Name {

Protocol contents such as Func GetInfo () do not need to implement curly braces []

}

Realize:

Type type name: Parent class (optional), Protocol 1, Protocol 2{

Concrete implementation of the Func GetInfo () {//Method implementation}

}

Note Static protocol, before adding class or Static, class representing classes (class Func GetName ()), static struct, enum enum enumimp:account{static func GetName () {}}

Extensions and Protocols