Functions and Closures

Argument Labels

Swift argument labels make function calls read like short phrases.

Name the call-site meaning

argument_labels.swift 
func makeLabel(for item: String, count: Int) -> String {
    return "\(item): \(count)"
}

let count = 
let label = makeLabel(for: "tickets", count: count)

print(label)

func makeLabel(for item: String, count: Int) -> String {
    return "\(item): \(count)"
}

let count = 
let label = makeLabel(for: "tickets", count: count)

print(label)

func makeLabel(for item: String, count: Int) -> String {
    return "\(item): \(count)"
}

let count = 
let label = makeLabel(for: "tickets", count: count)

print(label)
labels The external label appears at the call site, while the parameter name is used inside the function body.