In Swift, how to insert formatted Int value into String?
<p>This seems like a super basic question, but I just can't seem to find the answer anywhere :-(  I am able to do this in Objective C, but I am getting stuck in Swift.</p>

<p>What I need to do:</p>

<ol>
<li>Take an Integer value</li>
<li>Format it into a localized string</li>
<li>Inject the value into another string using the <code>stringWithFormat</code> equivalent method (since the other string is localized as well, which is not shown in simplified examples below)</li>
</ol>

<p>How it's easily done in <strong>Objective C</strong> -- this works:</p>

<pre><code>    // points is of type NSNumber *

    NSNumberFormatter *formatter = [NSNumberFormatter new];
    formatter.locale             = [NSLocale currentLocale];
    formatter.numberStyle        = NSNumberFormatterDecimalStyle;

    NSString *ptsString = [formatter stringFromNumber:points];
    NSString *message   = [NSString stringWithFormat:@"You've earned %@ points", ptsString];
</code></pre>

<p>My best attempt at doing this in <strong>Swift</strong> -- compiler error on last line:</p>

<pre><code>    // points is of type Int

    let formatter         = NSNumberFormatter()
    formatter.locale      = NSLocale.currentLocale()
    formatter.numberStyle = NSNumberFormatterStyle.DecimalStyle

    let ptsString = formatter.stringFromNumber(points)!
    let message   = String(format: "You've earned %@ points", arguments: ptsString)
</code></pre>

<p>I'm getting the following error in Xcode on that last line:</p>

<pre><code>"Cannot convert value of type 'String' to expected argument type '[CVarArgType]'"
</code></pre>

<p><em>(In my actual code, the message into which I want to insert the points value is itself localized as well, but I have simplified this example, as I'm getting the exact same error in both cases.)</em></p>

<p>What am I missing here..?</p>

<p>Thanks so much for any help,</p>

<p>Erik</p>