A Humorous Lesson in Object-Oriented Programming

The following was taken from Snopes.com and is a somewhat embellished story from 1999.

Mutant Marsupials Take Up Arms Against Australian Air Force

The reuse of some object-oriented code has caused tactical headaches for Australia's armed forces. As virtual reality simulators assume larger roles in helicopter combat training , programmers have gone to great lengths to increase the realism of the their scenarios, including detailed landscapes and — in the case of the Northern Territory's Operation Phoenix — herds of kangaroos (since groups of disturbed animals might well give away a helicopters position).

The head of the Defense Science and Technology Organization's Land Operations/Simulations division reportedly instructed developers to model the local marsupials' movements and reaction to helicopters.

Being efficient programmers, they just re-appropriated some code originally used to model infantry detachments reactions under the same stimuli, changed the mapped icon from a soldier to a kangaroo, and increased the figures' speed of movement.

Eager to demonstrate their flying skills for some visiting American pilots, the hotshot Aussies "buzzed" the virtual kangaroos in low flight during a simulation. The kangaroos scattered, as predicted, and the Americans nodded appreciatively . . .and then did a double-take as the kangaroos reappeared from behind a hill and launched a barrage of stinger missiles at the hapless helicopter. (Apparently the programmers had forgotten the remove "that" part of the infantry coding).

The lesson? Objects are defined with certain attributes, and any new object defined in terms of the old one inherits all the attributes. The embarrassed programmers had learned to be careful when reusing object-oriented code, and the Yanks left with the utmost respect for the Australian wildlife.

Simulator supervisors report that pilots from that point onwards have strictly avoided kangaroos, just as they were meant to.