title: Making immutable function parameter mutable
body: <p>I have a method that takes in an array and inside that method I want to append some objects to that array. Since Swifts parameters to functions are immutable I'm unable to do so. It is vital that I maintain the same reference to that array since that array is going to be used in a table view to display data. My code is as follows:</p>
  
  <pre><code>class func loadData(tableView: UITableView, results: [LocationInfo]){
      print("\n Data fetch started \n")
      let root = FIRDatabase.database().reference()
      let locationSummary = root.child("LocSummary")
  
      locationSummary.observeSingleEvent(of: .value,with: { (snapshot) in
          for item in snapshot.children{
              let locationInfo = LocationInfo(snapshot: item as! FIRDataSnapshot)
              results.append(locationInfo) // ERROR IS WITH THIS
  
          }
          DispatchQueue.main.async {
              print("\n data fetch completed \n ")
              tableView.reloadData()
              print("After on completion method \(results.count)")
  
          }
      })
  }
  </code></pre>
  
  <p>How can I append data to this array while maintaining the same reference.</p>