Code Complexity – A Complex Matter

Eats Shoots and Leaves?

Eats Shoots and Leaves?

“Oh we didn’t use your code in the end,” said an ex-colleague some time after I’d left a previous employer, “nobody could understand it.” I was a little taken aback because I’d thought the code was particularly clear given the complexity of what I was doing.

I could understand that some less experienced developers might have had trouble with it, but to someone experienced I didn’t think it would be an issue.  This left me feeling distinctly sheepish – should I have written the code in the way I did? Instead of going for ultimate performance could I have simplified it, got enough of a performance gain and achieved a greater degree of maintainability?

I felt sheepish because code that nobody understands is a big development problem for 2 reasons. The first is that at some point someone will need to understand it – that’s going to take time and development time is expensive. The second is that there is a danger that someone who doesn’t understand it (even if they think they do) modifies it and makes a mistake. Often people under pressure to fix bugs have to make guesses and sometimes they’re wrong – it might appear to fix the issue but it may actually unleash a greater demon that’s much, much harder to find.

Sometimes code does need to be complex: the earth for instance is far from round and it’s hard to avoid some pretty hideous maths if you need to work with its geometry. That’s excusable but every effort should be made to lay the code out clearly and comment well. What’s not acceptable is needless complexity through bad design, bad coding style, bad layout, lack of commenting or even in some cases developers showboating.

A good developer is not the one who writes really clever, complex code that nobody else understands. It’s the one who solves complex problems by writing simple, easy to understand code. Maintainability is the key, that’s what business needs to succeed.