Test your knowledge

1. We can add the following type of initializers to a class with extensions:

   1. Convenience initializers.

   2. Designated initializers.

   3. Primary initializers.

2. We can add the following type of properties to a class with extensions:

   1. Read/write stored type properties.

   2. Primary properties.

   3. Computed instance properties and computed type properties.

3. Convenience initializers are:

   1. Optional.

   2. Required.

   3. Required only in superclasses.

4. A convenience initializer acts as:

   1. A required initializer that doesn't need to call any other initializer.

   2. A secondary initializer that doesn't need to call any other initializer.

   3. A secondary initializer that always ends up calling a designated initializer.

5. If we declare the type for a property as UIPickerView!, Swift will treat the property as:

   1. An implicitly wrapped optional.

   2. An implicitly unwrapped optional.

   3. An exact equivalent of UIPickerView?.