Swift

let label = UILabel()

Objective-C

UILabel *label = [[UILabel alloc] init];
or
UILabel *label = [UILabel new]; // convenience method for calling alloc-init

Change the default font’s size

Swift

label.font = UIFont.systemFontOfSize(17)

Swift 3

label.font = UIFont.systemFont(ofSize: 17)

Objective-C

label.font = [UIFont systemFontOfSize:17];

Use a specific font weight

Swift

label.font = UIFont.systemFontOfSize(17, weight: UIFontWeightBold)

Swift3

label.font = UIFont.systemFont(ofSize: 17, weight: UIFontWeightBold)

Objective-C

label.font = [UIFont systemFontOfSize:17 weight:UIFontWeightBold];