How do I set a weight to SF Symbols for iOS 13?

I have this

Image(systemName: "arrow.right")

But how do I make it bold, semibold etc?

I am using the new SwiftUI.

When using the font modifier, set a weight to the font you're passing.

For example, if you want to use one of the default text styles (which I recommend, since they adapt to the user's Dynamic Type setting), you can do it like this:

Image(systemName: "arrow.right")
  .font(Font.title.weight(.ultraLight))

If you want to specify a font size, you can do it like this:

Image(systemName: "arrow.right")
  .font(Font.system(size: 60, weight: .ultraLight))

For UIKit, symbols can be configured as follows:

UIImage(systemName: "arrow.right",
        withConfiguration: UIImage.SymbolConfiguration(pointSize: 16, weight: .bold))

SwiftUI 1.0

I just wanted to also mention how to change the weight along with a custom font size.

HStack(spacing: 40) {
    Image(systemName: "moon.zzz")
        .font(Font.system(size: 60, weight: .ultraLight))
    Image(systemName: "moon.zzz")
        .font(Font.system(size: 60, weight: .light))
    Image(systemName: "moon.zzz")
        .font(Font.system(size: 60, weight: .regular))
    Image(systemName: "moon.zzz")
        .font(Font.system(size: 60, weight: .bold))
}

UIKit -- Swift 5 -- Xcode 11

If you only want to set the weight (so you don't mess up auto icon sizing), do this:

let configuration = UIImage.SymbolConfiguration(weight: .semibold)
UIImage(systemName: "trash", withConfiguration: configuration)

You can also wrap the Image with Text. With that you can use and assign the fontWeight() to Text:

Text(Image(systemName: "xmark"))
    .fontWeight(.semibold)

UIKit SWIFT 5.x

To set their attributes: create a configuration then pass it in as a parameter:

let imageConfig = UIImage.SymbolConfiguration(pointSize: 22, weight: .black, scale: .large)
let image = UIImage(systemName: "delete.right", withConfiguration: imageConfig)