How to find actual number of lines of UILabel?

Question

How can I find the actual number of lines of a UILabel after I have initialized it with a text and a font? I have set

Answer 1

Swift 5 (IOS 12.2)

Get max number of lines required for a label to render the text without truncation.

extension UILabel {
    var maxNumberOfLines: Int {
        let maxSize = CGSize(width: frame.size.width, height: CGFloat(MAXFLOAT))
        let text = (self.text ?? "") as NSString
        let textHeight = text.boundingRect(with: maxSize, options: .usesLineFragmentOrigin, attributes: [.font: font], context: nil).height
        let lineHeight = font.lineHeight
        return Int(ceil(textHeight / lineHeight))
    }
}

Get max number of lines can be displayed in a label with constrained bounds. Use this property after assigning text to label.

extension UILabel {
    var numberOfVisibleLines: Int {
        let maxSize = CGSize(width: frame.size.width, height: CGFloat(MAXFLOAT))
        let textHeight = sizeThatFits(maxSize).height
        let lineHeight = font.lineHeight
        return Int(ceil(textHeight / lineHeight))
    }
}

Usage

print(yourLabel.maxNumberOfLines)
print(yourLabel.numberOfVisibleLines)