如果数据类型为URL的变量为空，我如何检查Swift？

Question

I'm trying to check if my url is nil or not since I have a background thread that is getting the url from my database.

I tried doing this travelURL.absoluteString == "" and travelURL != nil but the problem still persists.

I declared my variable as var travelURL: URL!

Answer 1

You can use if let syntax:

if let url = travelURL {
    // Here you can use url, it is not nil
} else {
   // Here url is nil 
}