Downcasting, what’s up with that?

Just a short post today, or a question rather, on what must be the easiest subject I’ve written about yet. Though, I’ve caught myself making errors against it often. Nowadays I’m extra cautious when writing about inheritance.

What do you think about first when you hear “up”?

graph upviagra-pills

What do you think about first when you hear “down”?

down graph.png


Now, how do we programmers interpret upcasting and downcasting?


You upcast to an object which can do less, and you downcast to an object which can do more.

What’s up with that?

UPDATE: I have since started a discussion on this on Programmers Stack Exchange.

Author: Steven Jeuris

I have a PhD in Human-Computer Interaction and am currently working both as a software engineer at iMotions and as a postdoc at the Technical University of Denmark (DTU). This blend of research and development is the type of work which motivates and excites me the most. Currently, I am working on a distributed platform which enables researchers to conduct biometric research 'in the wild' (outside of the lab environment). I have almost 10 years of professional software development experience. Prior to academia, I worked for several years as a professional full-stack software developer at a game development company in Belgium: AIM Productions. I liked the work and colleagues at the company too much to give up entirely for further studies, so I decided to combine the two. In 2009 I started studying for my master in Game and Media Technology at the University of Utrecht in the Netherlands, from which I graduated in 2012.

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