Swift
return nil } } }
let circname = rectangle() circname.print?[0] = radius(radiusname: "Diameter")
let printing = circle() printing.area.append(radius(radiusname: "Units")) printing.area.append(radius(radiusname: "Meter")) circname.print = printing
var area = ["Radius": [35, 45, 78, 101], "Circle": [90, 45, 56]] area["Radius"]?[1] = 78 area["Circle"]?[1]--
println(area["Radius"]?[0]) println(area["Radius"]?[1]) println(area["Radius"]?[2]) println(area["Radius"]?[3])
println(area["Circle"]?[0]) println(area["Circle"]?[1]) println(area["Circle"]?[2]) When we run the above program using playground, we get the following result: Optional(35) Optional(78) Optional(78) Optional(101) Optional(90) Optional(44) Optional(56) 174