I'm fresh to C - used to scripting languages like, PHP, JS, Ruby etc. Got a query in regard to performance. I know one should not micro optimize too early - however, I'm writing a Ruby C Extension for Google SketchUp where I'm doing lots of 3D calculations so performance is a concern. (And this question is also for learning how C works.)

Often many iterations is done to process all the 3D data so I'm trying to work out what might be faster.

I'm wondering if accessing an array entry many times is faster if I make a pointer reference to that array entry? What would common practice be?

```
struct FooBar arr[10];
int i;
for ( i = 0; i < 10; i++ ) {
  arr[i].foo = 10;
  arr[i].bar = 20;
  arr[i].biz = 30;
  arr[i].baz = 40;
}

```

Would this be faster or slower? Why?

```
struct FooBar arr[10], *item;
int i;
for ( i = 0; i < 10; i++ ) {
  item = &arr[i];
  item->foo = 10;
  item->bar = 20;
  item->biz = 30;
  item->baz = 40;
}

```

I looked around and found discussions about variables vs pointers - where it was generally said that pointers required extra steps since it had to look up the address, then the value - but in general there wasn't a bit hit.

But what I was wondering was if accessing an array entry in C has much of a performance hit? In Ruby it is faster to make a reference to the entry if you need to access it many time - but that's Ruby...