PHP - remove element in multidimensional array

问题

I have this array:

Array ( 
[0] => Array ( [0] => b [1] => d [2] => **c** [3] =>a [4] => ) 

[1] => Array ( [0] => **c** [1] => a [2] => d [3] => [4] => ) 

[2] => Array ( [0] => b [1] => d [2] => a [3] => [4] => )

[3] => Array ( [0] => **c** [1] => d [2] => a [3] =>b [4] => )

)

and need to delete (unset?) all elements where value is "c" so that one ends up with:

Array ( 
[0] => Array ( **[0] => b [1] => d [2] => a [3] => [4] =>** ) 

[1] => Array ( **[0] => a [1] => d [2] => [3] =>** ) 

[2] => Array ( [0] => b [1] => d [2] => a [3] => [4] => )

[3] => Array ( **[0] => d [1] => a [2] =>b [3] =>** )

)

The element gets removed, and the other elements to shift up. I know that unset does not re-index the array. Cannot get to unset for all multidimensional arrays, but only with one array. Can the arrays be re-indexed afterwards? Appreciate it.

The code BELOW removes elements where the value is equal to "c" but the index of the first element is not re-indexed. Can anyone suggest a solution to re-indexing the inner arrays?

$i=0;
foreach ($array as $val)
    {
    foreach ($val as $key => $final_val)
        { 

        if ($final_val =="$search_value") 
            {
             unset($array[$i][$key]);
            }
        } 
    i = $i + 1;
    }

回答1:

The following code will do what you want:

<?php
$a = 1;
$b = 2;
$c = 3;
$d = 4;

$arr = array(
array ( $b, $d, $c, $a, $b),
array ($c, $a),
array ( $b, $d,  $c ),
array( $c, $d, $a, $b, $b)
);
echo "before:\n";
print_r($arr);

foreach($arr as $k1=>$q) {
  foreach($q as $k2=>$r) {
    if($r == $c) {
      unset($arr[$k1][$k2]);
    }
  }
}
echo "after:\n";
print_r($arr);
?>

Output:

before:
Array
(
    [0] => Array
        (
            [0] => 2
            [1] => 4
            [2] => 3
            [3] => 1
            [4] => 2
        )

    [1] => Array
        (
            [0] => 3
            [1] => 1
        )

    [2] => Array
        (
            [0] => 2
            [1] => 4
            [2] => 3
        )

    [3] => Array
        (
            [0] => 3
            [1] => 4
            [2] => 1
            [3] => 2
            [4] => 2
        )

)
after:
Array
(
    [0] => Array
        (
            [0] => 2
            [1] => 4
            [3] => 1
            [4] => 2
        )

    [1] => Array
        (
            [1] => 1
        )

    [2] => Array
        (
            [0] => 2
            [1] => 4
        )

    [3] => Array
        (
            [1] => 4
            [2] => 1
            [3] => 2
            [4] => 2
        )

)

As you can see, all the 3's have gone...

回答2:

Search the value in the sub array then unset it.

$search = 'c';
$result = array_map(function ($value) use ($search) {
   if(($key = array_search($search, $value)) !== false) {
      unset($value[$key]);
   }
   return $value;
}, $your_array);

Or you could use a loop too:

// this way change your original array
foreach ($your_array as &$sub_array) {
    if(($key = array_search($search, $sub_array)) !== false) {
        unset($sub_array[$key]);
    }
}
var_dump($your_array);

来源：https://stackoverflow.com/questions/21249041/php-remove-element-in-multidimensional-array

标签

arrays

multidimensional-array

elements