Question

How can I filter out the array entries with an odd or even index number?

Array (     [0] => string1     [1] => string2     [2] => string3     [3] => string4 ) 

I want it remove the [0] and [2] entries from the array. Or say I have 0,1,2,3,4,5,6,7,8,9; I would need to remove 0,2,4,6,8.

Answer 1

foreach($arr as $key => $value) if($key&1) unset($arr[$key]);

The above removes odd number positions from the array, to remove even number positions, use the following:

Instead if($key&1) you can use if(!($key&1))