Introduction To Protocols

What are Protocols?

In programming and software development, a protocol is a blueprint of methods, properties, and other requirements that suit a particular task or piece of functionality. Protocols define a set of rules and standards that allow different components of a software system to communicate with each other.

In Swift, protocols are a powerful feature that allows you to define a piece of functionality that can be adopted by classes, structures, and enumerations. Protocols can be thought of as interfaces in other programming languages.

Why Use Protocols?

Protocols are used for various reasons, including:

Encapsulation of behavior: Protocols allow you to define a set of behaviors that can be adopted by multiple types.
Code reusability: By defining a protocol, you can create different types that share the same functionality without code duplication.
Flexibility: Protocols enable different types to be used interchangeably, as long as they conform to the same protocol.

Defining a Protocol

Protocols are defined using the protocol keyword followed by the name of the protocol. Here is a simple example:

protocol Vehicle {
func startEngine()
}

In this example, we have defined a protocol named Vehicle with a single method startEngine.

Conforming to a Protocol

To adopt the protocol, a class, structure, or enumeration must implement the methods and properties defined by the protocol. Here is how we can conform a class to the Vehicle protocol:

class Car: Vehicle {
  func startEngine() {
    print("Car engine started")
  }
}

In this code, the Car class conforms to the Vehicle protocol by implementing the startEngine method.

Using Protocols

Once a class conforms to a protocol, you can use it in your code as follows:

let myCar = Car()
myCar.startEngine()

The output of the code will be:

Car engine started

Conclusion