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copied!<p>I had a bit of time over lunch:</p> <pre><code>public static void main(String[] args) { final int[] a = new int[250000000]; long t; for (int j = 0; j < 10; j++) { t = System.currentTimeMillis(); for (int i = 0, n = a.length; i < n; i++) { int x = a[i]; } System.out.println("n = a.length: " + (System.currentTimeMillis() - t)); t = System.currentTimeMillis(); for (int i = 0; i < a.length; i++) { int x = a[i]; } System.out.println("i < a.length: " + (System.currentTimeMillis() - t)); } } </code></pre> <p>The results:</p> <pre><code>n = a.length: 672 i < a.length: 516 n = a.length: 640 i < a.length: 516 n = a.length: 656 i < a.length: 516 n = a.length: 656 i < a.length: 516 n = a.length: 640 i < a.length: 532 n = a.length: 640 i < a.length: 531 n = a.length: 641 i < a.length: 516 n = a.length: 656 i < a.length: 531 n = a.length: 656 i < a.length: 516 n = a.length: 656 i < a.length: 516 </code></pre> <p>Notes:</p> <ol> <li>If you reverse the tests, then <code>n = a.length</code> shows as being faster than <code>i < a.length</code> by about half, probably due to garbage collection(?).</li> <li>I couldn't make <code>250000000</code> much larger because I got <code>OutOfMemoryError</code> at <code>270000000</code>.</li> </ol> <p>The point is, and it is the one everyone else has been making, you have to run Java out of memory and you still don't see a significant difference in speed between the two alternatives. Spend your development time on things that actually matter.</p>

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