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

Simplest way I know of

if NSClassFromString("NSURLQueryItem") != nil {
    println("NSURLQueryItem exists")
}else{
    println("NSURLQueryItem does not exists")
}