An exception: I don’t think there’s anything wrong with using i/j/k as loop index variables. I agree that if it’s a simple loop it should be a foreach, but if you need the index for some reason then i is the best possible name for it. Unless the author is particularly perverse, I know as soon as I see it that i is the loop index – it’s one of the most powerful conventions going.

An observation: Objective C attempts to solve the object.doStuff(realParam, true, false) problem by naming the parameters in the call as well as the definition.
As I understand it (I don’t actually program in Objective C) that call might look like [object doStuff:realparam useWidget:true bePersistant:false] . It looks a bit alien at first when you’re used only to function(arguments) syntax inherited from C, but I think I could get used to it.

dealing with Javascript (or most interpreted languages), small variables in a loop massively speed things up as well.

Just from experience…

May I ask why foreach is better than for loops? How is having an indexing variable a bad thing?
I believe I read somewhere that the for loop is more efficient than the foreach loop.

Rafferty

Have you disassembled the foreach loop to see how its byte code differs from regular for loops? What additional instructions are there? Have you written tests that time the two variety of loops? Would you share those timings. What JVM version are you working with?

I’ve never encountered a situation where the foreach loop was slower in anyway that I can measure. Hence my interest in your findings.

In addition I’m certain that modern compilers and JVM’s can make much better decisions about loop unrolling than I can.

Finally I assume that you’re doing these optimisations in code that has already proven to be bottleneck.

I wish I could give you more on the foreach other than my personal experience and “best Guess” – which is that in a foreach loop, each iteration has more calculations etc to do in order to “figure” out what it is that “Each” means, but if I iterate through an array of objects I am directly accessing the pointer via it’s index – no calcs required.

My grid loads 3000 rows in about 17 seconds with all of the functionality of the infragistics WebGrid (which takes closer to 2 and 1/2 minutes to render). Through the above tweaks, I gained much in the manner of speed.

For Compiled languages – I may just do the same for consistency sake though – unless I find a bottleneck!

-Tim