OperationHelloWorld

OperationHelloWorld

class PrintOperation: Operation {
    let stringToPrint: String
    init(stringToPrint: String = "I don't have manners") {
        self.stringToPrint = stringToPrint
        super.init()
    }
    override func main() {
        guard !isCancelled else { return }
        print(stringToPrint)
    }
}

let queue = OperationQueue()

let printOperation = PrintOperation(stringToPrint: "Hello, World!")

printOperation.completionBlock = {
    print("Done!")
}

queue.addOperation(printOperation)