Adding elements to optional arrays in Swift

Question

What is the proper way to append an element on the end of an optional array? Let's say I have an optional array, myArray, and I want to append '99' on the end. Append() does not work on a nil array, so the only solution I can find is the following, but it doesn't seem very elegant:

var myArray = [Int]?()  if myArray?.count > 0 {     myArray?.append(99) } else {     myArray = [99] } 

Answer 1

You can use the fact that methods called via optional chaining always return an optional value, which is nil if it was not possible to call the method:

if (myArray?.append(99)) == nil {     myArray = [99]  } 

If myArray != nil then myArray?.append(99) appends the new element and returns Void, so that the if-block is not executed.

If myArray == nil then myArray?.append(99) does nothing and returns nil, so that the if-block is executed and assigns an array value.