Count "truthy" values in a 2d array - php

Question

Given the following array $mm
Array
(
[147] => Array
(
[pts_m] =>
[pts_mreg] => 1
[pts_cg] => 1
)
[158] => Array
(
[pts_m] =>
[pts_mreg] =>
[pts_cg] => 0
)
[159] => Array
(
[pts_m] =>
[pts_mreg] => 1
[pts_cg] => 1
)
)
When I run count(array_filter($mm)) I get 3 as result since it is not recursive.
count(array_filter($mm), COUNT_RECURSIVE) also will not do because I actually need to run the array_filter recursively, and then count its result.
So my question is: how do I recursively run array_filter($mm) in this case?
My expected result here would be 4.
Please note that I am not using any callback so I can exclude false, null and empty.

Answer 1

From the PHP array_filter documentation:
//This function filters an array and remove all null values recursively.
<?php
function array_filter_recursive($input)
{
foreach ($input as &$value)
{
if (is_array($value))
{
$value = array_filter_recursive($value);
}
}
return array_filter($input);
}
?>
//Or with callback parameter (not tested) :
<?php
function array_filter_recursive($input, $callback = null)
{
foreach ($input as &$value)
{
if (is_array($value))
{
$value = array_filter_recursive($value, $callback);
}
}
return array_filter($input, $callback);
}
?>

Answer 2

Should work
$count = array_sum(array_map(function ($item) {
return ((int) !is_null($item['pts_m'])
+ ((int) !is_null($item['pts_mreg'])
+ ((int) !is_null($item['pts_cg']);
}, $array);
or maybe
$count = array_sum(array_map(function ($item) {
return array_sum(array_map('is_int', $item));
}, $array);
There are definitely many more possible solutions. If you want to use array_filter() (without callback) remember, that it treats 0 as false too and therefore it will remove any 0-value from the array.
If you are using PHP in a pre-5.3 version, I would use a foreach-loop
$count = 0;
foreach ($array as $item) {
$count += ((int) !is_null($item['pts_m'])
+ ((int) !is_null($item['pts_mreg'])
+ ((int) !is_null($item['pts_cg']);
}
Update
Regarding the comment below:
Thx #kc I actually want the method to remove false, 0, empty etc
When this is really only, what you want, the solution is very simple too.
But now I don't know, how to interpret
My expected result here would be 5.
Anyway, its short now :)
$result = array_map('array_filter', $array);
$count = array_map('count', $result);
$countSum = array_sum($count);
The resulting array looks like
Array
(
[147] => Array
(
[pts_mreg] => 1
[pts_cg] => 1
)
[158] => Array
(
)
[159] => Array
(
[pts_mreg] => 1
[pts_cg] => 1
)
)

Answer 3

A better alternative
One implementation that always worked for me is this one:
function filter_me(&$array) {
foreach ( $array as $key => $item ) {
is_array ( $item ) && $array [$key] = filter_me ( $item );
if (empty ( $array [$key] ))
unset ( $array [$key] );
}
return $array;
}
I notice that someone had created a similar function except that this one presents, in my opinion, few advantages:
you pass an array as reference (not its copy) and thus the algorithm is memory-friendly
no additional calls to array_filter which in reality involves:
the use of stack, ie. additional memory
some other operations, ie. CPU cycles
Benchmarks
A 64MB array
filter_me function finished in 0.8s AND the PHP allocated memory before starting the function was 65MB, when function returned it was 39.35MB !!!
array_filter_recursive function recommended above by Francois Deschenes had no chance; after 1s PHP Fatal error: Allowed memory size of 134217728 bytes exhausted
A 36MB array
filter_me function finished in 0.4s AND the PHP allocated memory before starting the function was 36.8MB, when function returned it was 15MB !!!
array_filter_recursive function succeeded this time in 0.6s and memory before/after was quite the same
I hope it helps.

Answer 4

This function effectively applies filter_recursive with a provided callback
class Arr {
public static function filter_recursive($array, $callback = NULL)
{
foreach ($array as $index => $value)
{
if (is_array($value))
{
$array[$index] = Arr::filter_recursive($value, $callback);
}
else
{
$array[$index] = call_user_func($callback, $value);
}
if ( ! $array[$index])
{
unset($array[$index]);
}
}
return $array;
}
}
And you'd use it this way:
Arr::filter_recursive($my_array, $my_callback);
This might help someone

Answer 5

I needed an array filter recursive function that would walk through all nodes (including arrays, so that we have the possibility to discard entire arrays), and so I came up with this:
public static function filterRecursive(array $array, callable $callback): array
{
foreach ($array as $k => $v) {
$res = call_user_func($callback, $v);
if (false === $res) {
unset($array[$k]);
} else {
if (is_array($v)) {
$array[$k] = self::filterRecursive($v, $callback);
}
}
}
return $array;
}
See more examples here: https://github.com/lingtalfi/Bat/blob/master/ArrayTool.md#filterrecursive

Answer 6

This should work for callback and mode support along with an optional support for depth.
function array_filter_recursive(array $array, callable $callback = null, int $mode = 0, int $depth = -1): array
{
foreach ($array as & $value) {
if ($depth != 0 && is_array($value)) {
$value = array_filter_recursive($value, $callback, $mode, $depth - 1);
}
}
if ($callback) {
return array_filter($array, $callback, $mode);
}
return array_filter($array);
}
Calling the function with $depth = 0 for nested arrays, will yield the same result as array_filter.

Answer 7

This strike me as an XY Problem.
Recursion is not necessary because the array has a consistent depth of 2 levels.
It is not necessary to generate an array of filtered elements so that you can traverse the filtered data to count it. Just traverse once and add 1 to the count variable whenever a truthy value is encountered.
The following snippet calls no functions (only language constructs -- foreach()) and therefore will be highly efficient.
Code: (Demo)
$truthyCount = 0;
foreach ($array as $row) {
foreach ($row as $v) {
$truthyCount += (bool) $v;
}
}
var_export($truthyCount);

Answer 8

<?php
$mm = array
(
147 => array
(
"pts_m" => "",
"pts_mreg" => 1,
"pts_cg" => 1
) ,
158 => array
(
"pts_m" => null ,
"pts_mreg" => null,
"pts_cg" => 0
),
159 => array
(
"pts_m" => "",
"pts_mreg" => 1,
"pts_cg" => 1
)
);
$count = 0;
foreach ($mm as $m) {
foreach ($m as $value) {
if($value !== false && $value !== "" && $value !== null) {
$count++;
}
}
}
echo $count;
?>