Explain Optional Chaining

Without going into too much detail, mention optional chaining so it's
not confusing that there is a question mark suffix (it's not currently
mentioned anywhere on the page).
This commit is contained in:
Keito Uchiyama 2015-01-20 14:52:31 -08:00
parent 6915f5bfd0
commit 7a55b4a9b1

View File

@ -445,7 +445,10 @@ class MyShape: Rect {
func grow() {
sideLength += 2
// Place a question mark after an optional property, method, or
// subscript to gracefully ignore a nil value and return nil
// instead of throwing a runtime error ("optional chaining").
if let allow = self.delegate?.canReshape?() {
// test for delegate then for method
self.delegate?.reshaped?()