Swift: define a variable then conditionally set it? - swift

Question

This is probably a very simple question...
Here I have some Swift code:
var url: NSURL
if (someValue > 1) {
var fullUrl = self.baseUrl + "?id=" + (someValue as! String);
var url = NSURL(string: fullUrl);
}
else {
var url = NSURL(string: self.baseUrl);
}
let req = NSURLRequest(URL: url);
webView.loadRequest(req);
As you can see, I need to conditionally initialize the url variable. However, the method I've used in just about every other strong-type language - initialize the variable then assign to it in the if statement - doesn't seem to be the Swiftly way of doing it.
The above code will refuse to compile with the error "variable 'url' used for being initialized" error. (Of course, from this program flow, you can see that url would always be initialized, but Swift apparently takes nothing for granted.)
Not defining the variable outside the if block results in an unknown identifier error - it seems variables defined inside an if block are scoped only within that block.
Short of just defining an empty NSURL object, is there a better way to do this?
Preferably I'd actually like to use let on this because the NSURL object will never change once it's been created - and Swift tends to recommend using let wherever possible. However, how would you use let in this scenario? (I tried it - the same types of errors occur. Swift is unhappy that I don't actually declare the object itself on the same line as the let statement, but using let inside the if block results in a scope issue.)

Answer 1

The problem is you're redefining url as var url = NSURL(string: self.baseUrl); within the context of the if-else so the url outside is never actually set.
This will fix the error and allow you to use let for url.
let url: NSURL
if (someValue > 1) {
var fullUrl = self.baseUrl + "?id=" + (someValue as! String);
url = NSURL(string: fullUrl);
} else {
url = NSURL(string: self.baseUrl);
}
let req = NSURLRequest(URL: url);
webView.loadRequest(req);

Answer 2

You are redeclaring your property each time you try to set it. Try:
url = /*stuff here*/;
inside your if statements instead of:
var url = /*stuff here*/;

Answer 3

You have to define outside of the {}, that sets it's scope. In your code you're redefining url in the if and the else, you need to remove the re-declaration of "var" so that you can assign your url to the url out of the scope of the if / else statement.
You can use another if statement to check for nil and unwrap it if it's not nil, like
if url != nil {
let req = NSURLRequest(URL: url!)
}

Answer 4

You variable url need to be conditional do something like this.
var url: NSURL?
if (someValue > 1) {
var fullUrl = self.baseUrl + "?id=" + (someValue as! String);
url = NSURL(string: fullUrl);
}
else {
url = NSURL(string: self.baseUrl);
}
let req = NSURLRequest(URL: url);
webView.loadRequest(req);