Using NSTimer to print to console in a playground

Question

Given the function "printTime" that prints 3 statements (H/M/S) what is the exact syntax for calling this function using NSTimer interrupts once per second?

Possible duplicate of [Using NSTimer in swift playground](http://stackoverflow.com/questions/29232334/using-nstimer-in-swift-playground) — nhgrif, Mar 29 '16 at 00:55

score 2 · Answer 1 · answered Mar 29 '16 at 03:43

Try this:

import Foundation
import XCPlayground

class Wrapper: NSObject {
    static let formatter: NSDateFormatter = {
        let formatter = NSDateFormatter()
        formatter.dateFormat = "HH:mm:ss"
        return formatter
    }()

    class func printTime() {
        print(formatter.stringFromDate(NSDate()))
    }

}

let timer = NSTimer.scheduledTimerWithTimeInterval(1, target: Wrapper.self, selector: #selector(Wrapper.printTime), userInfo: nil, repeats: true)

XCPlaygroundPage.currentPage.needsIndefiniteExecution = true

You need to wrap the printTime function in an object to send to NSTimer. The loop will end when you change the playground's code.

Using NSTimer to print to console in a playground

1 Answers1