How to make part of a string bold in iOS?

Question

I want to make some part of a text string bold.

Eg: This is to be bold. This is normal string.

In Android, it can be easily achieved by using spannable strings. What is its equivalent in iOS?

Answer 1

Yes, it can be achieved with NSAttributedString:

NSString *yourString = @"This is to be bold. This is normal string.";
NSMutableAttributedString *yourAttributedString = [[NSMutableAttributedString alloc] initWithString:yourString];
NSString *boldString = @"This is to be bold";
NSRange boldRange = [yourString rangeOfString:boldString];
[yourAttributedString addAttribute: NSFontAttributeName value:[UIFont boldSystemFontOfSize:12] range:boldRange];
[yourLabel setAttributedText: yourAttributedString];

Answer 2

Swift version:

@IBOutlet var theLabel: UILabel!
@IBOutlet var theTextview: UITextView!

        let theString = "Please satisfy three of the following password conditions" as NSString
        let theAttributedString = NSMutableAttributedString(string: theString as String)

        let boldString = "three"
        let boldRange = theString.range(of: boldString)
        let font = UIFont.boldSystemFont(ofSize: 20)

        theAttributedString.addAttribute(NSFontAttributeName, value: font, range: boldRange)
        theLabel.attributedText = theAttributedString
        theTextview.attributedText = theAttributedString

Answer 3

You can achieve this using NSMutableAttributedString.

Refer Apple docs about NSMutableAttributedString.

I'd tried this answer's code to get bold and normal font in an UILabel.