PHP - unset in a multidimensional array

Question

I have this array $output which looks like this:

Array(
    [0] => Array(
        [0] => 1a
        [1] => 1b
        [2] => 1c
    )
    [1] =&g         


        

Answer 1

You'd use a combination of array_map and array_splice:

function removeSecond( array &$arr )
{
    array_splice( $arr, 1, 1 );
}
$out = array_map( 'removeSecond', $input );

The problem with unset is that it will leave the indexes as they were:

$ php -r '$arr = array(array(0,1,2)); unset($arr[0][1]); var_dump($arr);'
array(1) {
  [0]=>
  array(2) {
    [0]=>
    int(0)
    [2]=>
    int(2)
  }
}

While splice will update the indexes:

$ php -r '$arr = array(array(0,1,2)); array_splice($arr[0], 1, 1); var_dump($arr);'
array(1) {
  [0]=>
  array(2) {
    [0]=>
    int(0)
    [1]=>
    int(2)
  }
}

Answer 2

Clean and neat:

$f = function(&$a,$k) { unset($a[1]); };
array_walk($arr, $f);

Or:

array_walk($arr, function (&$a, $k) {
  unset($a[1]); 
});

Answer 3

You can iterate over the array, and unset() what you want in each sub-array:

foreach($output as &$item) {
    unset($item[2]);
}
unset($item); // unset reference

Answer 4

Can't be done with a simple command, but you can use a loop:

foreach(array_keys($output) as $key) {
   unset($output[$key][1]);
}

Answer 5

foreach($array as $key=>$val){ unset($val[1]); }