Filter out differences between correlated data sets from two multidimensional arrays

Question

I have 2 arrays:

$big_array = [
    [
        ['correct' => FALSE, 'answer' => 'false answer1'],
        ['correct' => FALSE, 'answer' => 'false answer2'],
        ['correct' => FALSE, 'answer' => 'false answer3'],
        ['correct' => TRUE, 'answer' => 'correct answer'],
    ]
];

$small_array = [
    [
        ['correct' => FALSE, 'answer' => 'false answer1'],
    ]
];

I want to make array_diff($big_array, $small_array) but it's not working how I want it to.

Currently, it gives me an empty array as a result, where I want the outcome to be:

$outcome_array = [
    [
        ['correct' => FALSE, 'answer' => 'false answer2'],
        ['correct' => FALSE, 'answer' => 'false answer3'],
        ['correct' => TRUE, 'answer' => 'correct answer'],
    ]
];

Answer 1

yes you can use below function to get you perfect answer

function arrayRecursiveDiff($aArray1, $aArray2) {
  $aReturn = array();

  foreach ($aArray1 as $mKey => $mValue) {
    if (array_key_exists($mKey, $aArray2)) {
      if (is_array($mValue)) {
        $aRecursiveDiff = arrayRecursiveDiff($mValue, $aArray2[$mKey]);
        if (count($aRecursiveDiff)) { $aReturn[$mKey] = $aRecursiveDiff; }
      } else {
        if ($mValue != $aArray2[$mKey]) {
          $aReturn[$mKey] = $mValue;
        }
      }
    } else {
      $aReturn[$mKey] = $mValue;
    }
  }
  return $aReturn;
} 

  $arr1 =    arrayRecursiveDiff($big_array,$small_array);

output

as you need

Array

(
    [0] => Array
        (
            [1] => Array
                (
                    [correct] => 
                    [answer] => false answer2
                )

            [2] => Array
                (
                    [correct] => 
                    [answer] => false answer3
                )

            [3] => Array
                (
                    [correct] => 1
                    [answer] => correct answer
                )

        )

)

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