Swift: Programmatically make UILabel bold without changing its size?

Question

I have a UILabel created programmatically. I would like to make the text of the label bold without specifying font size. So far I have only found:

UIFont.boldSystemFont(ofSize: CGFloat)

This is what I have exactly:

let titleLabel = UILabel()
let fontSize: CGFloat = 26
titleLabel.font = UIFont.boldSystemFont(ofSize: titleLabelFontSize)

But this way I am also setting the size. I would like to avoid that. Is there a way?

If there is no way, what would be a good workaround in Swift?

Thank you!

Something like that: `titleLabel.font = UIFont.boldSystemFont(ofSize: titleLabel.font.pointSize)`? — Larme, Oct 12 '16 at 12:54
Possible duplicate of [How do I set bold and italic on UILabel of iPhone/iPad?](http://stackoverflow.com/questions/4713236/how-do-i-set-bold-and-italic-on-uilabel-of-iphone-ipad) — Supratik Majumdar, Oct 12 '16 at 12:59
This may help: [How can I get the font size and font name of a UILabel?](http://stackoverflow.com/questions/4866138/how-can-i-get-the-font-size-and-font-name-of-a-uilabel) — Ozgur Vatansever, Oct 12 '16 at 13:05

score 49 · Accepted Answer · answered Oct 12 '16 at 12:58

49

Why not just:

titleLabel.font = UIFont.boldSystemFont(ofSize: titleLabel.font.pointSize)

answered Oct 12 '16 at 12:58

Chris Vig

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Thanks! Worked great! – user1269290 Oct 12 '16 at 17:13
Thanks Works for me. – Satish Babariya Jul 21 '17 at 09:45
You are my hero! – Haroun Hajem Jan 26 '22 at 23:00
If I could upvote 100 times, I would. Thank you. – connr Mar 29 '22 at 19:01

score 17 · Answer 2 · edited Oct 25 '17 at 17:31

To just make the Font bold without altering the font size you could create an extension like this (which is based off the answer here:

extension UIFont {

    func withTraits(traits:UIFontDescriptorSymbolicTraits...) -> UIFont {
        let descriptor = self.fontDescriptor()
        .fontDescriptorWithSymbolicTraits(UIFontDescriptorSymbolicTraits(traits))
        return UIFont(descriptor: descriptor, size: 0)
    }

    func bold() -> UIFont {
        return withTraits(.TraitBold)
    }

}

So that way you could use it like this:

let titleLabel = UILabel()
titleLabel.font = titleLabel.font.bold() //no need to include size!

Update for Swift 4 syntax:

extension UIFont {

    func withTraits(traits:UIFontDescriptorSymbolicTraits...) -> UIFont {
        let descriptor = self.fontDescriptor               
           .withSymbolicTraits(UIFontDescriptorSymbolicTraits(traits))
        return UIFont(descriptor: descriptor!, size: 0)
    }

    func bold() -> UIFont {
        return withTraits(traits: .traitBold)
    }
}

Thank you! I went with a different answer but I've learned from your post. — user1269290, Oct 12 '16 at 17:14

Swift: Programmatically make UILabel bold without changing its size?

2 Answers2