php delete elements in multidimensional array

In PHP development, it is often necessary to delete an element in a multi-dimensional array to ensure the integrity and standardization of the data. This article will introduce several common methods to delete elements in multi-dimensional arrays.

1. Use the unset function

The unset function is a common method to delete variables in PHP. It can also be used to delete elements in multi-dimensional arrays.

First, we need to determine the position of the element to be deleted. This can be achieved in two ways:

(1) Use subscript

$arr ​​= array(

'a' => array('b', 'c', 'd'),
'e' => array('f', 'g', 'h')

);

//Delete the 'c' element in the $arr['a'] array
unset($arr'a');

（ 2) Use the key name

$arr ​​= array(

'a' => array('b', 'c', 'd'),
'e' => array('f', 'g', 'h')

);

//Delete the 'e' element in the $arr array
unset($arr ['e']);

The advantage of using the unset function is that the code is concise and easy to understand. The disadvantage is that it cannot return deleted elements and cannot perform some processing operations.

2. Use the array_splice function

The array_splice function is a function in PHP that replaces and deletes elements from an array. With this function we can easily delete one or more elements from a multidimensional array.

Same as the unset function, we need to first determine the position of the element to be deleted:

$arr ​​= array(

'a' => array('b', 'c', 'd'),
'e' => array('f', 'g', 'h')

);

//Delete The 'c' element in the $arr['a'] array
array_splice($arr['a'], 1, 1);

//Delete the 'e' element in the $arr array
array_splice($arr, 1, 1);

The advantage of using the array_splice function is that it can return deleted elements and perform some processing operations. The disadvantage is that the code is relatively complex.

3. Use the array_filter function

The array_filter function can filter the elements in the array according to the specified callback function. We can use this function to delete elements in the multi-dimensional array.

$arr ​​= array(

'a' => array('b', 'c', 'd'),
'e' => array('f', 'g', 'h')

);

//Delete the 'c' element in the $arr['a'] array
$arr[' a'] = array_filter($arr['a'], function($value, $key) {

return $value != 'c';

}, ARRAY_FILTER_USE_BOTH);

//Delete the ' in the $arr array e' element
$arr ​​= array_filter($arr, function($value, $key) {

return $key != 'e';

}, ARRAY_FILTER_USE_BOTH);

The advantage of using the array_filter function is that it supports callback functions , you can perform some complex logical operations, but the disadvantage is that the code is cumbersome and difficult to understand.

4. Use recursive functions

For the deletion operation of multi-dimensional arrays, we can also use recursive functions to delete.

function array_delete(&$array, $key) {

foreach($array as $k => &$v) {
    if($k === $key) {
        unset($array[$k]);
    }
    elseif(is_array($v)) {
        array_delete($v, $key);
    }
}

}

The advantage of using recursive function is that it is simple and easy to implement and the logic is clear. The disadvantage is that it cannot support returning The deleted element.

To sum up, there are many ways to delete elements in multi-dimensional arrays in PHP. In actual development, you can choose according to your needs to achieve the best performance and effect.

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