PHP - Get the key that has a value in multiple indexes - php

Question

I have the below array:
$myArray = [
[
"name" => null,
"price" => [
"height" => 0.0098974902792506,
"left" => 0.8385,
"page" => 1,
"top" => 0.51290208554259,
"width" => 0.0275,
],
],
[
"name" => null
"price" => [
"height" => 0.0098974902792506,
"left" => 0.838,
"page" => 1,
"top" => 0.56981265464829,
"width" => 0.028,
]
],
[
"name" => null
"price" => [
"height" => 0.010250972074938,
"left" => 0.5905,
"page" => 1,
"top" => 0.44114528101803,
"width" => 0.0285,
]
]
];
I am trying to check the array and get the name of the key that has a value (is not null) in each array. In the above example, this would be price.
However, the array could also look like this:
[
[
"name" => null,
"price" => [
"height" => 0.0098974902792506,
"left" => 0.8385,
"page" => 1,
"top" => 0.51290208554259,
"width" => 0.0275,
],
],
[
"name" => null
"price" => null
],
[
"name" => null
"price" => null
]
]
In this case, there is not an array key that has a value in all of the arrays.
Below is my attempt to achieve this:
$originalKeyWithValue = null;
foreach($myArray as $key => $item)
{
$originalKeyWithValue = array_key_first($item);
if (isset($myArray[$key+1])) {
$nextKeyWithValue = array_key_first($myArray[$key+1]);
if($originalKeyWithValue != $nextKeyWithValue){
$originalKeyWithValue = $nextKeyWithValue;
}
}
}
return $originalKeyWithValue;
However the code above returns name as the key, even though it is null in all of the arrays in $myArray.

Answer 1

This is what would I do:
// I take first element of array as a source for indexes
foreach ($myArray[0] as $index => $item) {
// next I extract all elements from all subarrays under current `$index`
$values = array_column($myArray, $index);
// then I filter values to remove nulls.
// This also removes 0, empty arrays, false,
// so maybe you should change filter process
$values_filtered = array_filter($values);
// if number of filtered items is same as in original array - no nulls found
if (count($values_filtered) === count($values)) {
echo $index;
// optionally
// break;
}
}

Answer 2

Although there is an accepted answer, I thought I would share a way to do this using Laravel collections.
$uniqueKeysWithValues = collect($myArray)->map(function($item){
return array_keys( collect($item)->filter()->toArray() ); //filter will remove all null
})->flatten()->unique();
This approach will give you all keys that has values in it, even if there are values in both keys.