数组快速行为

Question

So im messing around with swift arrays, and they seem to be quite missleading in some areas although most of the stuff was fixed in xcode 6.1

i wanna make an array of arrays but it need to store the references, not only the values. how can i store the references of the arrays so that updates will also take effect on the "outer array"?

var a1 = [1,2]

var allarrays = [[Int]]()

allarrays.append(a1)

a1.append(99)

allarrays

allarys still gives me me [[1,2]] here, instead of [[1,2,99]]

Answer 1

Unfortunately (for your specific problem) swift array are value types, and as such they are always passed by value.

A workaround that might work (with inherent drawbacks) is to use NSMutableArray , which is a reference type (ie a class) instead:

var a1: NSMutableArray = [1,2]

var allarrays: NSMutableArray = NSMutableArray()

allarrays.addObject(a1)

a1.addObject(99)

allarrays // [[1, 2, 99]]