Line Breaks and Number of Lines based on data in Swift Label (Programmatically)

Change the values in story board of label values to 

Lines --> 0

Line Break -- > Word wrap

override func viewDidLoad() {        super.viewDidLoad(){self.chatdisplayTableview.estimatedRowHeight = 600.0;        self.chatdisplayTableview.rowHeight = UITableViewAutomaticDimension;        self.chatdisplayTableview.setNeedsLayout()        self.chatdisplayTableview.layoutIfNeeded()}