Swift将创建的struct实例返回给函数

Question

// Here in file: Struct.swift is where I define the layout of my structs.

struct coin 
{
    var coinYear        = String("")
    var userID          = String("")
    var coinSellCoinID  = String("")
    var coinImageURL    = String("")
    var mintYear        = String("")
    var about           = String("")
    var allowBarter     = String("")
}

/*

1. Here in file FirstViewController.swift I get a coin ID value from an input box and then process a button click and build a URL string.

2. I then send that URL to fetchCoinJSON function to get JSON text

*/

@IBAction func btnSubmitCoinID(sender: AnyObject)
{
    let temp = coinID.text
    let theCoinURL = NSURL(string: MyVariables.url + "getCoinInfo.php?coinID=" + temp)
    fetchCoinJSON(theCoinURL!)
}

// file: fetchJson.swift With the URL to get the JSON string I then get the JSON string and pass that string onto parseCoinJson function.

       func fetchCoinJSON(theurl: NSURL)
        {
            var error: NSError?

var notWorking = coin()

MyVariables.rawCoinJSON =

NSString(contentsOfURL: theurl, encoding: NSUTF8StringEncoding, error: &error)!

var data: NSData =
MyVariables.rawCoinJSON.dataUsingEncoding(NSUTF8StringEncoding)!

    let anyObj: AnyObject? = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &error)
            println("Error: \(error)")

    notWorking = parseCoinJson(anyObj!) <--- var notWorking = nil
            NSLog("OoOoOoOoOoOoOoO")
            println(notWorking.coinWeight) <--- logs null
        }

//file ParseJSON.swift here I parse the JSON and set the corresponding struct values. Using NSLog I know that c.CoinYear does contain the correct value along with all the other values. However

return c

gives error: ParseJSON.swift:95:16: 'coin' is not convertible to '()'

    func parseCoinJson(anyObj:AnyObject)
    {
        if  anyObj is Array<AnyObject>
        {
            var c = coin()
            for json in anyObj as! Array<AnyObject>
            {
                c.userID = (json["userid"] as AnyObject? as? String) ?? String("") ?? String ("")
                c.mintYear = (json["mintyear"] as AnyObject? as? String) ?? String("") ?? String ("")
                c.coinActiveStatus = (json["isActive"] as AnyObject? as? String) ?? String("") ?? String ("")
                c.coinSellCoinID = (json["sellcoinid"] as AnyObject? as? String) ?? String("") ?? String ("")
                c.coinImageURL = (json["coinImageURL"] as AnyObject? as? String) ?? String("") ?? String ("")
                c.about = (json["about"] as  AnyObject? as? String) ?? String("") ?? String ("")
                c.allowBarter = (json["allowBarter"] as  AnyObject? as? String) ?? String("") ?? String ("")

....

    }
            return c
        }
    }

Answer 1

func parseCoinJson(anyObj:AnyObject)

This function returns Void , which is () . You then return coin . You meant your function to be:

func parseCoinJson(anyObj:AnyObject) -> Coin

Note that types should always be leading caps. So this should be struct Coin .