Check for class existence in Swift

Question

I want to use NSURLQueryItem in my Swift iOS app. However, that class is only available since iOS 8, but my app should also run on iOS 7. How would I check for class existence i

Answer 1

Swift 2.0 provides us with a simple and natural way to do this.It is called API Availability Checking.Because NSURLQueryItem class is only available since iOS8.0,you can do in this style to check it at runtime.

    if #available(iOS 8.0, *) {
        // NSURLQueryItem is available

    } else {
        // Fallback on earlier versions
    }