PHP - Check if any nested array is not empty - php

Question

If i have a nested array as follows, how can I check if any of the dates arrays are NOT empty?
$myArray = [
'1' => [ 'dates' => []],
'2' => [ 'dates' => []],
'3' => [ 'dates' => []],
...
]
I know I can check this by doing a foreach loop:
$datesAreEmpty = true;
foreach($myArray as $item) {
if (!empty($item['dates'])) {
$datesAreEmpty = false;
}
}
Is there a more elegant way to do this?

Answer 1

You need to do in 3 steps
check each element is_array()
if Yes, then check size($element)
if its greater than 0 then true otherwise false

Answer 2

More elegant? No, I don't think so. Actually, you can break the loop after the first non-empty to make this check short-circuit, that's a tiny improvement, but this is THE way to do it.
Using array_walk (which will be mentioned in minutes I'm sure) is slower and less readable; also, there are tricky solutions with serialization (finding non-empty date strings by strpos or regex) but you don't gain anything by applying them.
Stick with this solution, and use a break on first hit. #chefstip ;)

Answer 3

Using second argument for count will count you all items in array including subarrays. This is not a solution for all cases as in other answers, and has some initial assumptions which can be not clear, but still:
// Suppose you have array of your structure
$myArray = [
'1' => ['dates' => []],
'2' => ['dates' => []],
'3' => ['dates' => []],
];
// compare
var_dump(count($myArray), count($myArray, true));
// you see `3` and `6`
// - 3 is count of outer elements
// - 6 is count of all elements
// Now if there're no other keys in subarrays except `dates`
// you can expect that `count` of all elements is __always__
// twice bigger than `count` of outer elements
// When you add some value to `dates`:
$myArray = [
'1' => ['dates' => ['date-1']],
'2' => ['dates' => []],
'3' => ['dates' => []],
];
// compare
var_dump(count($myArray), count($myArray, true));
// you see `3` (outer elements) and `7` (all elements)
// So, you have __not empty__ `dates` when `count` of all elements
// is more than doubled count of outer elements:
$not_empty_dates = 2 * count($myArray) < count($myArray, true);
// Of course if you have other keys in subarrays
// code should be changed accordingly, that's why
// it is not clear solution, but still it can be used
A working fiddle https://3v4l.org/TanG4.

Answer 4

Can be done iteratively with array_filter:
// This will be empty if all array elements are empty.
$filtered = array_filter($myArray, '_filter_empty');
/**
* Recursively remove empty elements from array.
*/
function _filter_empty($element) {
if (!is_array($element)) {
return !empty($element);
}
return array_filter($element, '_filter_empty');
}