Running on the latest Google Chrome browser (Version 22.0.1229.79) on an iMac with Mountain Lion, you may encounter unexpected results when executing the following code snippet:
var arr = [1, 3, 5];
console.log(arr);
delete arr[1];
console.log(arr);
console.log(arr.pop());
console.log(arr);
The output displayed will be:
[1, undefined × 2]
[1, undefined × 2]
5
[1, undefined × 1]
Interestingly, Firefox exhibits a similar behavior in certain scenarios. Is this an issue with both Chrome and Firefox or does it stem from the use of array delete and console.log? It seems unlikely that both browsers would have the same bug. Perhaps, there is something unique about how console.log interacts with arrays.