Swift 3转换

Question

I have written a code for concurrent API calls in swift 2.2. When I change from swift 2.2 to swift 3, I am facing issue with syntax of swift. Help me out

    let endPoints = [.email, .others]
    let fetchGroup = dispatch_group_create()
    let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_apply(endPoints.count, queue) { (index)  in
        let enumType = endPoints[index]
        switch enumType {
        case .email:
           //Make email api call
            break
        case .others:
           //Make other api 
            break
        default:
            break
        }
    }

    dispatch_group_notify(fetchGroup, dispatch_get_main_queue()) {
        if endPoints.count > 0 {
          fail("error")
        }
    }

Answer 1

Do you still remember dispatch_apply() . Well, it's still there and got a new name. From now on you have to call concurrentPerform()

 let endPoints = [.email, .others]
    let fetchGroup = DispatchGroup()
    let queue = DispatchQueue.global (qos : .default)
    DispatchQueue.concurrentPerform(iterations: endPoints.count)
   { (index)  in
        let enumType = endPoints[index]
        switch enumType {
        case .email:
            //Make email api call
            break
        case .others:
            //Make other api
            break
        default:
            break
        }
    }
    DispatchGroup().notify(queue: DispatchQueue.main) {
        if endPoints.count > 0 {
            fail("error")
        }
    }

for more information see this