dynamic cell height based on labels

Question

I have just started with IOS development and i am facing issue with UiTableView.I want to create an Expandable cell.So after researching i tried but the code works in some phones and not some phones.So i wanted some help.

Storyboard

At beginning i wanted to show only first 3 labels and then on click i want to show all the labels

Code

//to calculate expanded height
    func expandedHeight() -> CGFloat
        {
            let data = arrayDrugs[selectedIndex!.row]

            let cell = tableView.dequeueReusableCellWithIdentifier("expandedCell") as! UDCell

            let height = returnLableHeight(cell.lblProducts, fontSize: 16, text: data.packedProd) +
                returnLableHeight(cell.lblSecondData, fontSize: 15, text: data.dose) +
                returnLableHeight(cell.lblThirdData, fontSize: 15, text: data.secondData) +
                returnLableHeight(cell.lblFourthData, fontSize: 15, text: data.thirdData) +
                returnLableHeight(cell.lblFifthData, fontSize: 15, text: data.fourthData) +
                returnLableHeight(cell.lblSixthData, fontSize: 15, text: data.fifthData) +
                returnLableHeight(cell.lblSeventhData, fontSize: 15, text: data.sixthData)
            print(height);
            print((cell.contentView.systemLayoutSizeFittingSize(UILayoutFittingExpandedSize).height)+1)
            cell.sizeToFit()
            cell.setNeedsLayout()
            cell.layoutIfNeeded()

            return (cell.contentView.systemLayoutSizeFittingSize(UILayoutFittingExpandedSize).height);

        }

//to calculate collapsed height

        func collapseHeight(indexPath:NSIndexPath) -> CGFloat{


            let data = arrayDrugs[indexPath.row]

            let cell = tableView.dequeueReusableCellWithIdentifier("expandedCell") as! UDCell

            let height = returnLableHeight(cell.lblProducts, fontSize: 16, text: data.packedProd) +
            returnLableHeight(cell.lblSecondData, fontSize: 15, text: data.dose) +
            returnLableHeight(cell.lblThirdData, fontSize: 15, text: data.secondData)



            //print(height);
           // print((cell.contentView.systemLayoutSizeFittingSize(UILayoutFittingExpandedSize).height)+1)
            cell.sizeToFit()
            cell.setNeedsLayout()
            cell.layoutIfNeeded()

            return (height+120);

        }

//calculate label height
func returnLableHeight(label:UILabel,fontSize:CGFloat,text:NSAttributedString) -> CGFloat{

        label.numberOfLines = 0
        label.lineBreakMode = NSLineBreakMode.ByWordWrapping
        label.font = UIFont.systemFontOfSize(fontSize)
        label.preferredMaxLayoutWidth = self.view.frame.width-40;
        label.attributedText = text
//        let rect:CGRect = text.boundingRectWithSize(CGSizeMake(self.view.frame.width-25,CGFloat.max), options: NSStringDrawingOptions.UsesLineFragmentOrigin, context:nil )//hear u will get nearer height not the exact value
//        let requredSize:CGRect = rect

        label.sizeToFit()

        //print(requredSize.height)
        return label.frame.height
    }