++i vs i++

[Ronald Schild]

In the following code:

for( int i = 0 ; i < 10 ; i++ )

Would ++i have been faster, execution-wise? I read somewhere way back (in Programming Gems I believe) that even in such cases, extra work must be done to make sure i can be incremented 1 after it's value is used in the expression (for i++ that is). It was based on c++, but I am wondering if i++ and ++i makes any difference here for java.

Thanks in advance.

[Guido Sautter]

Try out printing the value of i within the loop with both variants, ad see what you get ... Hint:
- i++ is a post-increment
- ++i is a pre-increment

[Campbell Ritchie]

Leave speed of execution as your last priority.
There is very little difference between ++i and i++ compared to the remainder of the loop, and I don't think there will be a difference in the body of the loops.

It is customary to use i++ when it is on its own. Since a for loop is a standardised construct, you will make maintenance much more difficult if you use uncoventional formats.

[Ronald Schild]

But there is a difference?

I mean,

for( int i ; i < 10 ; ++i )

for( int i ; i < 10 ; i++ )

don't have much difference in maintainability. With the same results,
the difference on performance would be my motivation to go with it.

I was just wondering about this, with the quality matrix aside of course. And I understand that design patterns and bottleneck analysis have a much greater impact on improving performance, but for the sake of adventure I tell you!

So...does it actually have a difference? Why is i++ the standard then I wonder.

[Joanne Neal]

If you're really that worried about it why don't you try disassembling it and see what instructions are actually used.

[Ronald Schild]

I guess it comes to that. Thanks for the tip though