[admin]

Recursively searching and removing a value from a multidimensional array in PHP

Topic

[admin]

Up

0

Down

Using the code

Assuming we want to remove all the elements containing “FirstValue” from an array, for example:
Hide Copy Code

$value = “FirstValue”; //value/element we want to remove

And we have the following multidimensional array:
Hide Copy Code

$array[“First”] = “FirstValue”;
$array[“Second”] = “SecondValue”;
$array[“Third”][“First”] = “FirstValue”;
$array[“Third”][“Second”] = “SecondValue”;
$array[“Fourth”][“Third”][“First”] = “FirstValue”;
$array[“Fourth”][“Third”][“Second”] = “SecondValue”;
$array[“Fifth”][“Fourth”][“Third”][“First”] = “FirstValue”;
$array[“Fifth”][“Fourth”][“Third”][“Second”] = “SecondValue”;

Using a simple print_r($array) on the above array, will print the following:
Hide Shrink Copy Code

Array
(
[First] => FirstValue
[Second] => SecondValue
[Third] => Array
(
[First] => FirstValue
[Second] => SecondValue
)

[Fourth] => Array
(
[Third] => Array
(
[First] => FirstValue
[Second] => SecondValue
)

)

[Fifth] => Array
(
[Fourth] => Array
(
[Third] => Array
(
[First] => FirstValue
[Second] => SecondValue
)

)

)
)

In order to remove all the elements containing the value “FirstValue” from this multidimensional array, we call the recursiveRemoval($array, $value) function as follows:
Hide Copy Code

recursiveRemoval($array, $value);

The recursiveRemoval function code is as follows:
Hide Copy Code

function recursiveRemoval(&$array, $val)
{
if(is_array($array))
{
foreach($array as $key=>&$arrayElement)
{
if(is_array($arrayElement))
{
recursiveRemoval($arrayElement, $val);
}
else
{
if($arrayElement == $val)
{
unset($array[$key]);
}
}
}
}
}

First thing we’re doing is checking if the array passed to the function is actually an array. If array passed is an array, we iterate through its elements. If the element is also an array (our array is not a one dimensional array), we recursively call the function recursiveRemoval($arrayElement, $val) again to break the multidimensional array into one dimensional arrays.

At the end, we process the one dimensional array elements, and we compare them to the passed value we want to remove, and we unset the key of the array ($array[$key]).

[Author]

Replies