Get the number of lines in UILabel iOS8

I'm seeing lots of deprecated answers for this question:

How do I calculate the number of lines in use in a UILabel based of its set text?

I know that I need to set the UILabel to have bounds that resize with word wrapping. In this way, I could detect the height of my UILabel and adjust an NSLayoutConstraint for the height of my UITableViewCell. Basically my problem plain and simple is:

How can I determine my UILabel's number of lines in use(based of descriptionLabel.text) or height in order to resize My UITableView's UITableViewCells which contain my UILabel.

Currently I have used this code:

descriptionLabel = [[UILabel alloc] initWithFrame:CGRectMake(30, 30, 270, 65)];
descriptionLabel.textColor = [UIColor blackColor];
descriptionLabel.numberOfLines = 0;
descriptionLabel.adjustsFontSizeToFitWidth = YES;