This is a swift extension for NSURL so you can parse the query string and get back a dictionary of the variables.

getKeyVals

extension NSURL {
    func getKeyVals() -> Dictionary<String, String>? {
        var results = [String:String]()
        var keyValues = self.query?.componentsSeparatedByString("&")
        if keyValues?.count > 0 {
            for pair in keyValues! {
                let kv = pair.componentsSeparatedByString("=")
                if kv.count > 1 {
                    results.updateValue(kv[1], forKey: kv[0])
                }
            }
            
        }
        return results
    }
}

extension URL {
    var queryItems: [String: String]? {
        return URLComponents(url: self, resolvingAgainstBaseURL: false)?
            .queryItems?
            .flatMap { $0.dictionaryRepresentation }
            .reduce([:], +)
    }
}

extension URLQueryItem {
    var dictionaryRepresentation: [String: String]? {
        if let value = value {
            return [name: value]
        }
        return nil
    }
}

Works with Swift 3. ;)

I tried the above solution by @mihai8804858 with Swift 3 / Xcode 8 but I couldn't get it to work. The "+" in the .reduce line of the URL extension produced a compile error: "ambiguous reference to member +". Mihai, I would still love to try out your solution - any chance you can clarify what is going on in thereduce line?

I was able to get @nevstad's NSURL extension working with Swift 3 so wanted to share that. It worked perfectly for my purpose (parsing a universal deep link URL).

extension NSURL {
    var queryItems: [String: String]? {
        var params = [String: String]()
        return NSURLComponents(url: self as URL, resolvingAgainstBaseURL: false)?
            .queryItems?
            .reduce([:], { (_, item) -> [String: String] in
                params[item.name] = item.value
                return params
            })
    }
 }

Used like this (it returned a [String : String] array):

 let url = NSURL(string: myURLString)
 if let queryString = url?.queryItems {
     print(queryString)
     for (index, item) in queryString.enumerated() {
         print(item.key)
         print(item.value)
     }
 }

extension URL {
    var queryItems: [String: String]? {
        return URLComponents(url: self, resolvingAgainstBaseURL: false)?
            .queryItems?
            .flatMap { $0.dictionaryRepresentation }
            .reduce([:], +)
    }
}

extension URLQueryItem {
    var dictionaryRepresentation: [String: String]? {
        if let value = value {
            return [name: value]
        }
        return nil
    }
}

func +<Key, Value> (lhs: [Key: Value], rhs: [Key: Value]) -> [Key: Value] {
    var result = lhs
    rhs.forEach{ result[$0] = $1 }
    return result
}

This works great for Swift 3

Cleaned up Swift 3 version without operator overloading:

extension URL {
    public var queryItems: [String: String] {
        var params = [String: String]()
        return URLComponents(url: self, resolvingAgainstBaseURL: false)?
            .queryItems?
            .reduce([:], { (_, item) -> [String: String] in
                params[item.name] = item.value
                return params
            }) ?? [:]
    }  
}

I don't like that much using reduce for side effects, this also works and is more readable IMO:

var params = [String: String]()
queryItems?.forEach { item in
    params[item.name] = item.value
}
return params

I also would put, for consistency, this in an extension of URLComponents (instead of directly in URL), which contains accessors for all the other parts of the URL.

@i-schuetz your solution can lose information. a perfectly cromulent query might look like ?name=Alice&name=Bob&name=Ted&name=Carol. If you ran your fragment on that queryItem list params["name"] would only return Carol

Here's an extension to URL that works with Swift 4.2

extension URL {
    private func splitQuery(_ query: String) -> [String: [String]] {
        return query.components(separatedBy: "&").map { $0.components(separatedBy: "=") }.reduce(into: [String: [String]]()) { result, element in
            guard !element.isEmpty,
                let key = element[0].removingPercentEncoding,
                let value = element.count >= 2 ? element[1].removingPercentEncoding : "" else { return }
            var values = result[key, default: [String]()]
            values.append(value)
            result[key] = values
        }
    }

    var fragmentItems: [String: [String]] {
        guard let fragment = self.fragment else {
            return [:]
        }

        return splitQuery(fragment)
    }

    var queryItems: [String: [String]] {
        guard let query = self.query else {
            return [:]
        }

        return splitQuery(query)
    }
}

// queryItems has the same behavior as fragmentItems

let test = URL(string: "http://example.com#name=Alice%20Barker&name=Bob&job=developer")!
test.fragmentItems // ["name": ["Alice Barker", "Bob"], "job": ["developer"]]
test.fragmentItems["name"] // Optional(["Alice Barker", "Bob"])

let test2 = URL(string: "http://example.com#name")!
test2.fragmentItems // ["name": [""]]
test2.fragmentItems["name"] // Optional([""])

let test3 = URL(string: "http://example.com#")!
test3.fragmentItems // ["": [""]]
test3.fragmentItems["name"] // nil

let test4 = URL(string: "http://example.com")!
test4.fragmentItems // [:]
test4.fragmentItems["name"] // nil