Programming Quote by Armando Fox
““When Ruby programmers say that some class “quacks like an Array,” they usually mean that it’s not necessarily an Array nor a descendant of Array, but it responds to most of the same methods as Array and can therefore be used wherever an Array would be used.””
About This Quote
Source Talk: Programming Languages, Stanford CS 242, 2015
A class can be used like an Array if it implements the same methods, even without inheriting from Array.
In simple terms: Non‑Array class can act like an Array by matching its interface.
Key Takeaway
Design objects to match required interfaces.
Themes
polymorphism
interface
software design
Mood
technical
analytical
Type
educational
explanatory
When to use this quote
- API design
- library usage
- code reuse
- testing
- refactoring
Key Concepts
duck typing
method compatibility
Questions to Reflect On
- What methods must your class implement to be interchangeable?
- How does duck typing affect code safety?
A Different Perspective
If the class lacks subtle Array behaviors, substitution may fail.
![“Where there's a will, there's a way. Hackers tend to find a way. Code is also expanding. More lines of code means more probability that there is an exploit that can be [used].” quote by Michael Demon Calce](https://sms4smile.com/quotes/img-quotes/9a1/michael-demon-calce-34963_code_where-there-s-a-will-there-s-a-way-hacke_2391716.jpg)
