NSAttributedString example that illustrates adding attributes to a String and setting the attributedText property on a UILabel

AttributedStringExample.swift

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var nameLabel: UILabel!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let text = "stockholm, sweden"
        let attributedText = NSMutableAttributedString.init(string: "stockholm, sweden", attributes: [:])
        let range1 = (text as NSString).range(of: "stockholm")
        let range2 = (text as NSString).range(of: "sweden")
        attributedText.addAttributes([NSAttributedString.Key.font : UIFont.systemFont(ofSize: 40, weight: .bold),
                                      NSAttributedString.Key.foregroundColor : UIColor.blue
                                    ],
                                     range: range1)
        attributedText.addAttributes([NSAttributedString.Key.underlineStyle : NSUnderlineStyle.double.rawValue,
                                      NSAttributedString.Key.foregroundColor : UIColor.orange,
                                      NSAttributedString.Key.underlineColor : UIColor.black,
                                      NSAttributedString.Key.font : UIFont.systemFont(ofSize: 24, weight: .medium)
                                    ],
                                     range: range2)
        nameLabel.attributedText = attributedText
    }
}