Swift allows nesting types within other types. This is done by defining a type in another type's definition. There is no standard syntax for this.
Let's look at a way we can nest types in Swift.
class A {var b = B()class B {var C;}}
In the code above, class B is defined inside the type definition of class A. This is a very simple way to nest types in Swift. Let's look at an example.
class Car {var eng = PowerUnit()class PowerUnit{var PowerUnitName = "Toyota 1.8 L 2ZR-FE Dual VVT-i";var Manufacturer = "Toyota"var EngineName = "2ZR-FE Dual VVT-i"var Displacement = "1798";var Transmission = "7-speed CVT-i";func fetchPowerUnitDetails() -> String {return "Manufacturer: \(self.Manufacturer), EngineName: \(self.EngineName), Displacement: \(self.Displacement), Transmission: \(self.Transmission)"}}}var car = Car()print(car.eng.fetchPowerUnitDetails())
In the code above:
Lines 1–15: We define a class, Car.
Line 2: We declare a variable eng of type PowerUnit.
Lines 4–14: We define a class PowerUnit inside class Car.
Lines 5–9: We declare some variables in the class Powerunit.
Lines 11–13: We define a function fetchPowerUnitDetails() in the class PowerUnit.
Line 16: We declare a variable of type Car.
Line 17: We call the fetchPowerUnitDetails() method of the eng variable of car.
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