Protocol Parameters - Swift Programming

Functions can accept any value that conforms to a protocol.

Pass conforming values

protocol_parameters.swift

protocol PrintableStatus {
    func statusText() -> String
}

struct Job: PrintableStatus {
    let name: String
    let finished: Bool

    func statusText() -> String {
        return finished ? "\(name):done" : "\(name):open"
    }
}

func renderStatus(_ item: PrintableStatus) -> String {
    return item.statusText()
}

let finished = 
let job = Job(name: "build", finished: finished)
let output = renderStatus(job)

print(output)

protocol PrintableStatus {
    func statusText() -> String
}

struct Job: PrintableStatus {
    let name: String
    let finished: Bool

    func statusText() -> String {
        return finished ? "\(name):done" : "\(name):open"
    }
}

func renderStatus(_ item: PrintableStatus) -> String {
    return item.statusText()
}

let finished = 
let job = Job(name: "build", finished: finished)
let output = renderStatus(job)

print(output)

protocol type A protocol parameter lets a function depend on required behavior instead of a specific concrete type.