Making text bold using attributed string in swift

Solution 1:

Usage:

let label = UILabel()
label.attributedText =
    NSMutableAttributedString()
        .bold("Address: ")
        .normal(" Kathmandu, Nepal\n\n")
        .orangeHighlight(" Email: ")
        .blackHighlight(" [email protected] ")
        .bold("\n\nCopyright: ")
        .underlined(" All rights reserved. 2020.")

Result:

Here is a neat way to make a combination of bold and normal texts in a single label plus some other bonus methods.

Extension: Swift 5.*

extension NSMutableAttributedString {
    var fontSize:CGFloat { return 14 }
    var boldFont:UIFont { return UIFont(name: "AvenirNext-Bold", size: fontSize) ?? UIFont.boldSystemFont(ofSize: fontSize) }
    var normalFont:UIFont { return UIFont(name: "AvenirNext-Regular", size: fontSize) ?? UIFont.systemFont(ofSize: fontSize)}
    
    func bold(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font : boldFont
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    
    func normal(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font : normalFont,
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    /* Other styling methods */
    func orangeHighlight(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font :  normalFont,
            .foregroundColor : UIColor.white,
            .backgroundColor : UIColor.orange
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    
    func blackHighlight(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font :  normalFont,
            .foregroundColor : UIColor.white,
            .backgroundColor : UIColor.black
            
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    
    func underlined(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font :  normalFont,
            .underlineStyle : NSUnderlineStyle.single.rawValue
            
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
}

Note: If compiler is missing UIFont/UIColor, replace them with NSFont/NSColor.

Solution 2:

var normalText = "Hi am normal"

var boldText  = "And I am BOLD!"

var attributedString = NSMutableAttributedString(string:normalText)

var attrs = [NSAttributedString.Key.font : UIFont.boldSystemFont(ofSize: 15)]
var boldString = NSMutableAttributedString(string: boldText, attributes:attrs)

attributedString.append(boldString)

When you want to assign it to a label:

yourLabel.attributedText = attributedString