Remove specific records from associative array key in php - php

Question

Hi I have an array that contains two arrays that has the following structure:
categories [
"lvl0" => array:2 [
0 => "Cleaning"
1 => "Bread"
]
"lvl1" => array:2 [
0 => null
1 => "Bread > rolls"
]
]
I would like to remove any records of NULL from the 'lvl1' array but have not been able to find the correct method to do this.
I have tried:
array_filter($categories['lvl1'])
But this also removes all records associated to lvl1 and not just the NULL ones.
Any help would be greatly appreciated.
Thanks

Answer 1

array_filter() takes a callback as the second argument. If you don't provide it, it returns only records that aren't equal to boolean false. You can provide a simple callback that removes empty values.
array_filter() also uses a copy of your array (rather than a reference), so you need to use the return value.
For instance:
$categories = [
"lvl0" => [
"Cleaning",
"Bread"
],
"lvl1" => [
null,
"Bread > rolls"
]
];
$lvl1 = array_filter($categories['lvl1'], function($value) {
return !empty($value);
});
var_dump($lvl1);
That will return:
array(1) {
[1] =>
string(13) "Bread > rolls"
}

Answer 2

I was having the same issue on my last working day.Generally for associative array array_filter() needs the array key to filter out null, false etc values. But this small function help me to filter out NULL values without knowing the associative array key. Hope this will also help you, https://eval.in/881229
Code:
function array_filter_recursive($input)
{
foreach ($input as &$value)
{
if (is_array($value))
{
$value = array_filter_recursive($value);
}
}
return array_filter($input);
}
$categories = [
"lvl0" => [
"Cleaning",
"Bread"
],
"lvl1" => [
null,
"Bread > rolls"
]
];
$result = array_filter_recursive($categories);
print '<pre>';
print_r($result);
print '</pre>';
Output:
(
[lvl0] => Array
(
[0] => Cleaning
[1] => Bread
)
[lvl1] => Array
(
[1] => Bread > rolls
)
)
Ref: http://php.net/manual/en/function.array-filter.php#87581

Answer 3

Robbie Averill who commented on my post with the following solved the issue:
$categories['lvl1'] = array_filter($categories['lvl1']);