Appending tuples to an array of tuples

问题

My class declares an array

var laps: (start: NSDate!, end: NSDate!)[] = []

When a tuple is added to this array I'd like to be able to do something like

let now = NSDate()
var lap = (now, nil)
laps.append(lap)

But at the append I get the error Missing argument for parameter 'end' in call.

回答1:

I've tried to following, and it looked correct syntactically:

typealias MyTuple = (start: NSDate!, end: NSDate?)

then in the method, I did:

var laps: Array<MyTuple> = Array()
laps.append((NSDate.date(), nil))

回答2:

There's a bug in using .append with arrays of tuples. You can use the += operator instead:

laps += lap

来源：https://stackoverflow.com/questions/24575331/appending-tuples-to-an-array-of-tuples