Question

Is there a way of iterating through an array but performing an operation on every other element?
ie If I have an array with 13 elements how do I do something to only elements 2,4,6,8,10 and 12?

Answer 1

to fix cletuses answer for more speed and fix typos:

for ($i = 1, $j = count($array); $i < $j; $i += 2) {
    // code
}