Swift Tutorial - Tutorialspoint

var rectarea: circumference?

}

class radius {

let radiusname: String

init(radiusname: String) { self.radiusname = radiusname }

}

class circumference {

var circumName: String?

var circumNumber: String?

var circumarea: String?

func buildingIdentifier() - > String? {

if circumName != nil {

return circumName

} else if circumNumber != nil {

return circumNumber

} else {

return nil

}

}

}

let circname = rectangle()

if circname.print?.circleprint() != nil {

println("Area of circle is specified)")

} else {

println("Area of circle is not specified")

}

When we run the above program using playground, we get the following result:

Area of circle is not specified

The function circleprint() declared inside the circle() sub class is called by creating an
instance named 'circname'. The function will return a value if it contains some value