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Mastering Swift

You're reading from   Mastering Swift

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Product type Paperback
Published in Jun 2015
Publisher Packt
ISBN-13 9781784392154
Length 358 pages
Edition 1st Edition
Languages
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Author (1):
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Jon Hoffman Jon Hoffman
Author Profile Icon Jon Hoffman
Jon Hoffman
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Toc

Table of Contents (17) Chapters Close

Preface 1. Taking the First Steps with Swift FREE CHAPTER 2. Learning about Variables, Constants, Strings, and Operators 3. Using Collections and Cocoa Data Types 4. Control Flow and Functions 5. Classes and Structures 6. Working with XML and JSON Data 7. Custom Subscripting 8. Using Optional Type and Optional Chaining 9. Working with Generics 10. Working with Closures 11. Using Mix and Match 12. Concurrency and Parallelism in Swift 13. Swift Formatting and Style Guide 14. Network Development with Swift 15. Adopting Design Patterns in Swift Index

Overriding methods and properties


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 does prompt 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.

Overriding methods

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 what the new Plant class looks like with the getDetails() method added:

class Plant {
  var height = 0.0
  var age = 0
 
  func growHeight(inches: Double) {
    self.height +=  inches;
  }
  
  func getDetails() -> String {
    return "Plant Details"
  }
}

Now let's...

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