在Swift中追加[（String，Double）]

Question

I'm still learning Swift, and I am learning this Stock Web Service tutorial that I found in the Web. I am quite stuck in appending the extracted values from the service to my array. Below is the sample code.

Array Initialization

private var sampleStocks: [(String, Double)] = [("GOOG", +2.2), ("YHOO", +3.22), ("AAPL", -4.1)];

Appending

let values = (notification.userInfo as! Dictionary<String,NSArray>)
    let stocksReceived:NSArray = values[constantNotifUpdate]!;
    sampleStocks.removeAll();
    for quote in stocksReceived {
        let quoteDict:NSDictionary = quote as! NSDictionary;
        var changeInPercentString = quoteDict["ChangeinPercent"] as! String;
        let changeInPercentStringClean: String = changeInPercentString.substring(to: changeInPercentString.index(before: changeInPercentString.endIndex));
        var me: [(String,Double)] = [(quoteDict["symbol"] as! String, Double(changeInPercentStringClean))];
        sampleStocks.append(me);


    }

I always got this error of "Cannot convert of type [(String, Double)] to expected argument type (String, Double)".

May you please help me and give me a short run through?

Answer 1

var me: [(String,Double)] is an Array. What you need is a tuple. Declare the me variable like this:

var me: (String,Double) = (quoteDict["symbol"] as! String, Double(changeInPercentStringClean)!);

Answer 2

You can use in swift 3.0.2 by:

sampleStocks.append(contentsOf: me)

or

var me: (String,Double) = (quoteDict["symbol"] as! String, Double(changeInPercentStringClean))
sampleStocks.append(me)