combine-playground.swift

import UIKit
import Combine

// Just Publishers
let publisher = Just("Hello, world!")
let subscription = publisher.sink { (theString: String) in
    print(theString)
}

// Pass through subjects
let passThroughSubject = PassthroughSubject<String, Never>()
let passThroughSubscription = passThroughSubject.sink(receiveCompletion: { (completion: Subscribers.Completion<Never>) in
    print("Completed! \(completion)")
}) { (value: String) in
    print("Value is: \(value)")
}
passThroughSubject.send("Hello")
passThroughSubject.send("My")
passThroughSubject.send("Name")
passThroughSubject.send("Is")
passThroughSubject.send("Derrick")
passThroughSubject.send(completion: .finished)

// Current value subjects
let currentValueSubject = CurrentValueSubject<Int, Never>(1)
print(currentValueSubject.value)
currentValueSubject.send(100)