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07 Mar 2011, 15:44
James D. Maher (5 posts)

The Object diagram is elegantly simplistic and useful.

When you introduced the diagram, you said “We always draw the class to the RIGHT of the object”. I love words like “always”; it lets me believe that concepts CAN be simple.
But, when you describe the method search (to succesive super-classes), you draw the super-class ABOVE the child class. Why not to the RIGHT?

Isn’t the String class just an instance of the Object class? So, shouldn’t each succesive super-class just be drawn to the RIGHT? Or, am I over-simplifying?

Of course, such diagrams would get very wide and unwieldy. And, you could adjust the verbiage to say “follow the arrow”. However, rigid consistency to the practice of always drawing the class to the RIGHT would absolutely crystalize the idea (at least, for me). Consistent visual repetition would really drive the point home, maybe enough for me to truly internalize the concept.

On the other hand, maybe I’m just wrong?


01 Feb 2012, 14:10
Dave Thomas (366 posts)

Yes, String is an instance of object. But it is also a child of Object. When we’re doing method lookup, we aren’t following “instance_of”, but we’re looking up the chain at the parent.

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