How to find values which were found before inside multi array - php

Question

i do have currently following problem. I have to check if the array contains the exact same values and if they were found before.
int(3) wasn´t found before so it is 0,
int(8) wasn´t found before so it is 0,
int(5) wasn´t found before so it is 0,
int(8) was found before so it is 1,
int(3) and int(8) was not found together so it is 0, and so on.
I already tried it with array_unique but that didn´t work as i wanted
For example:
array(7) {
[2] => array(1) {
[0] => int(3)
}
[3] => array(1) {
[0] => int(8)
}
[4] => array(1) {
[0] => int(5)
}
[5] => array(1) {
[0] => int(8)
}
[6] => array(2) {
[0] => int(3)
[1] => int(8)
}
[7] => array(2) {
[0] => int(2)
[1] => int(5)
}
[8] => array(2) {
[0] => int(3)
[1] => int(8)
}
}
it must look something like this
array(7) {
[2] => array(1) {
[0] => int(0)
}
[3] => array(1) {
[0] => int(0)
}
[4] => array(1) {
[0] => int(0)
}
[5] => array(1) {
[0] => int(1)
}
[6] => array(1) {
[0] => int(0)
}
[7] => array(1) {
[0] => int(0)
}
[8] => array(1) {
[0] => int(1)
}
}

Answer 1

You could use array_map() and serialize():
<?php
$data = [
2 => [
3,
],
3 => [
8,
],
4 => [
5,
],
5 => [
8,
],
6 => [
3,
8,
],
7 => [
2,
5,
],
8 => [
3,
8,
],
];
$occurrences = [];
$mapped = array_map(function (array $values) use (&$occurrences) {
// create serialized representation of the values
// which we can use as an index
$index = serialize($values);
// haven't seen these values before
if (!array_key_exists($index, $occurrences)) {
$occurrences[$index] = 1;
return 0;
}
// increase our counter
$occurrences[$index]++;
return $occurrences[$index] - 1;
}, $data);
var_dump($mapped);
For reference, see:
http://php.net/manual/en/function.array-map.php
http://php.net/manual/en/function.serialize.php
For an example, see:
https://3v4l.org/oWBcS

Answer 2

<?php
$new_array = array();
$indicator = array();
$current_array = array(
"2" => array(3),
"3" => array(8),
"4" => array(5),
"5" => array(8),
"6" => array(3,8),
"7" => array(2,5),
"8" => array(3,8),
);
foreach($current_array as $key => $value){
if(!in_array($value, $new_array, true)){
$new_array[$key] = $value;
$indicator[$key] = false;
} else {
$indicator[$key] = true;
}
}
var_dump($indicator);