A common bug in published code

Post by ignifero » Thu, Apr 21, 2011, 9:37 PM UTC

Post by [deleted] » Thu, Apr 21, 2011, 9:41 PM UTC

nbpoole wrote: post #4

dalke wrote: post #3

The first few examples are fine. It's the unscaled ones later on, like "longarr[i] = (int) Math.random();" and especially "[Math.abs((int) Math.random()) % 3];" where the authors didn't notice that random() "returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0." Here's another extreme example: (int) Math.random() / Integer.MAX_VALUE % (maxScoreCount + 1); I eyeballed that about…

That's not true. Try running the following code: public class Test { public static void main(String[] args) { System.out.println("Test: " + (int)Math.random() * 100); System.out.println("Test: " + (int)(Math.random() * 100)); } } My results, from repeated tests: java Test Test: 0 Test: 59 java Test Test: 0 Test: 18 java Test Test: 0 Test: 72 java Test Test: 0 Test: 11

Post by ghewgill » Thu, Apr 21, 2011, 9:44 PM UTC

Post by Adrock » Thu, Apr 21, 2011, 9:53 PM UTC

Post by myelin » Thu, Apr 21, 2011, 10:21 PM UTC

baltcode wrote: post #17

Apparently, python only has 5 instances of the corresponding error: http://www.google.com/codesearch?hl=en&lr=&q=\s%2Bin... Python-Java flame-war, anyone?