How to print() to Xcode console in SwiftUI?

Question

So I tried to put a print statement while debugging in a SwiftUI View.

print("landmark: \(landmark)")

In the following body.

var body: some View {
    NavigationView {
        List {
            Toggle(isOn: $userData.showFavoritesOnly) {
                Text("Favorite only")
            }
            ForEach(landmarkData) { landmark in
                print("landmark: \(landmark)")
                if !self.userData.showFavoritesOnly || landmark.isFavorite {
                    NavigationButton(destination: LandmarkDetail(landmark: landmark)) {
                        LandmarkRow(landmark: landmark)
                    }
                }
            }
        }
       .navigationBarTitle(Text("Landmarks"))            
    }
}

Compiler errors out:

So, what is the proper way to print to console in SwiftUI?

EDIT: I made Landmark conform to CustomStringConvertible:

struct Landmark: Hashable, Codable, Identifiable, CustomStringConvertible {

var description: String { name+"\(id)" }

var id: Int
var name: String
.....

I still get the "String is not convertible to any" error. Should it work now?

Answer 1

At least in Xcode 12/Swift 5.3, you can easily add a print statement anywhere in a function builder by simply storing its return value in a wildcard, effectively ignoring it:

let _ = print("hi!") 

No setup or other verbosity needed!

Answer 2

Here's a helper Print( ... ) View that acts like a print( ... ) function but within a View

Put this in any of your view files

extension View {
    func Print(_ vars: Any...) -> some View {
        for v in vars { print(v) }
        return EmptyView()
    }
}

and use inside of body like so

Print("Here I am", varOne, varTwo ...)

or inside a ForEach {} like so

self.Print("Inside ForEach", varOne, varTwo ...)

Note: you might need to put Print() into a Group {} when combining with existing views