Wait for an async methods to finish in a for loop

Question

I have a for loop containing three asynchronous methods, and I want to make some treatment after this 3 async methods are finished.

 -(void)getAllUsersInformatio         


        

Answer 1

Rop Answer with swift:

func processData()
{
    let group: dispatch_group_t  = dispatch_group_create()

    for item in data as! Object {
        dispatch_group_enter(group)
        item.process(completion: {() -> (Void) in
          dispatch_group_leave(group)
        })
      }

    dispatch_group_notify(group, dispatch_get_main_queue(), {
        //Do whatever you want
      })
}