URL and string interpolation

Question

It seems URL initializer (string: "") refuses to initialize properly when using string interpolation. The problem is, when I use something like

let url = URL(string: "http://192.168.1.1")

it works, but the following

let host = "192.168.1.1"
let url = URL(string: "http://\(host)")

does not and url = nil.

In Playground both work but not in the code. I did double check if the variable host is properly set.

Any idea?

Answer 1

Had a similar problem.

This worked in Swift 2 but broke in Swift 3 (I bounce between 2 of our apps, similar to Facebook & Facebook Messenger):

var userId: Int!
var userType: String!

// userId and userType are set by some code somewhere else...

if let url = URL(string: "anotherappicreated://?userId=\(userId)&userType=\(userType)") {
    UIApplication.shared.openURL(url)   // Open our other app
}

In Swift 2 implicitly unwrapped optionals (variables declared with the !) worked without having to unwrap them. In Swift 3 it seems you must explicitly unwrap optionals:

var userId: Int!
var userType: String!

// userId and userType are set by some code somewhere else...

if let userId = userId,        // <-- HAD TO ADD THIS
    let userType = userType,   // <-- AND THIS
    let url = URL(string: "anotherappicreated://?userId=\(userId)&userType=\(userType)") {
    UIApplication.shared.openURL(url)   // Open our other app
}