To override a method, property, or subscript, we need to prefix the definition with the override keyword. This tells the compiler that we intend to override something in the super class and that we did not make a duplicate definition by mistake. The override keyword prompts the Swift compiler to verify that the super class (or one of its parents) has a matching declaration that can be overridden. If it cannot find a matching declaration in one of the super classes, an error will be thrown.
Let's look at how we would override a method. We will start by adding a getDetails() method to the Plant class that we will then override in the child classes. The following code shows how the new Plant class looks with the getDetails() method added:
class Plant {
var height = 0.0
var age = 0
func growHeight(inches: Double) {
self.height += inches;
}
func getDetails() -> String {
...