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

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    // Background work
       for(User *user in users){
          [self getUserInfo:user];
       }

    dispatch_async(dispatch_get_main_queue(), ^{
     //reload tableview , this is on main thread.
    });
});