Remove “columns” from the subarrays of a two dimensional array

Question

I have a simple, two dimensional array like this:

Array
    (
        [0] => Array
            (
                [0] => abc
                [1] => 1         


        

Answer 1

Anything wrong with just looping through it?

for ( $i = 0; $i < sizeof($input); $i++ ) {
    for ( $j = 0; $j < $n; $j++ ) {
        $output[$i][$j] = $input[$i][$j];
    }
}
return $output;

Answer 2

Even with array_walk :

array_walk(
    $aYourArray,
    function(&$aSubRow){
        $aSubRow = array_slice($aSubRow, 0, 2);
    }
);

Answer 3

const MAX = 2; // maximum number of elements
foreach ($array as &$element) {
    $element = array_slice($element, 0, MAX);
}

Answer 4

foreach($array as $key=> $element)
{
    for($i=0; $i<$n; $i++)
    {
        $newArray[$key][$i] = $element[$i];
    }
}

Not sure if there is a more efficient method.