Swift
} }
let rectname = rectangle()
if let rectarea = rectname.print?.cprint { println("Area of rectangle is \(rectarea)") }
else { println("Rectangle Area is not specified")
} When we run the above program using playground, we get the following result: Rectangle Area is not specified
Calling Methods Through Optional Chaining class rectangle { var print: circle? } class circle { var area = [radius]() var cprint: Int { return area.count } subscript(i: Int) -> radius { get { return area[i] } set { area[i] = newValue } }
func circleprint() { println("Area of Circle is: \(cprint)") } 167