Compare Multidimensional Arrays in PHP

Compare multidimensional arrays in PHP

The simplest way I know:

$a == $b;

Note that you can also use the ===. The difference between them is:

1. With Double equals ==, order is important:

   $a = array(0 => 'a', 1 => 'b');
   $b = array(1 => 'b', 0 => 'a');
   var_dump($a == $b);  // true
   var_dump($a === $b); // false
   

2. With Triple equals ===, types matter:

   $a = array(0, 1);
   $b = array('0', '1');
   var_dump($a == $b);  // true
   var_dump($a === $b); // false
   

Reference: Array operators

Compare multidimensional array values by key in php

I need compare values of the products by each key. To highlight rows
in the compare table where price, quantity, availability, or
manufacturer is different.

If you want to highlight all products unless all of them have exactly the same price, quantity, availability, or manufacturer.

function:

function productsIdentical(array &$products) : bool
{
    if (count($products) < 2) {
        throw new \InvalidArgumentException("You should pass at least 2 products to compare");
    }

    $compare = '';
    foreach ($products as $product) {
        ksort($product); //to make comparison of key order insensitive
        $sha = sha1(json_encode($product));
        if (empty($compare)) {
            $compare = $sha;
        } elseif ($sha !== $compare) {
            return false;
        }
    }
    return true;
}

returns true only if all products' fields have exactly the same keys and value, otherwise it returns false

so you use it this way:

$identicalFlag = productsIdentical($all_products);
if ($identicalFlag === false) {
    echo "Products are not identical:" . PHP_EOL;

    $nonIdenticalProductsArr = array_keys($all_products);
    echo "Non identical products are:" . PHP_EOL;
    print_r($nonIdenticalProductsArr);

    //do your styling  on $nonIdenticalProducts

} else {
    echo "Products are identical" . PHP_EOL;
}

Output:

for identical products:

Products are identical

for non identical:

Products are not identical:
Non identical products are:
Array
(
    [0] => product_1
    [1] => product_2
    [2] => product_3
)

Or if you want to detect every product field that is not the same across all products in the array use this function:

function getFieldsNonIdentical(array &$products) : array
{
    if (count($products) < 2) {
        throw new \InvalidArgumentException("You should pass at least 2 products to compare");
    }

    $compareArr = [];
    $keyDifferentArr = [];
    foreach ($products as $product) {
        foreach($product as $key => $val) {
            if (!key_exists($key, $compareArr)) {
                $compareArr[$key] = $val;
            } elseif ($compareArr[$key] !== $val) {
                $keyDifferentArr[$key] = true;
            }
        }
    }
    return array_keys($keyDifferentArr);
}

this way:

$fieldsNonIdentical = getFieldsNonIdentical($all_products);

if (!empty($fieldsNonIdentical)) {
    echo "Fields that are non identical:" . PHP_EOL;

    print_r($fieldsNonIdentical);

    //do your styling

    $nonIdenticalStyle = 'style="background-color: lightblue;"';
    $styleArr = [];
    foreach ($fieldsNonIdentical as $key => $value) {
        $styleArr[$value] = $nonIdenticalStyle;
    }

    echo "Non Identical fields styling is:" . PHP_EOL;
    print_r($styleArr);
} else {
    echo "All fields in all products are the same." . PHP_EOL;
}

Output

for identical:

All fields in all products are the same.

for non identical:

Fields that are non identical:
Array
(
    [0] => price
    [1] => manufacturer
)
Non Identical fields styling is:
Array
(
    [price] => style="background-color: lightblue;"
    [manufacturer] => style="background-color: lightblue;"
)

PHP Compare two multidimensional arrays by key and value

function calculateDifference($array1, $array2){
  $difference = array();
  foreach($array1 as $key => $value){
    if(isset($array2[$key])){
      $difference[$key] = abs($array1[$key] - $array2[$key]);
    }else{
      $difference[$key] = $value;
    }
  }
  foreach($array2 as $key => $value){
    if(isset($array1[$key])){
      $difference[$key] = abs($array1[$key] - $array2[$key]);
    }else{
      $difference[$key] = $value;
    }
  }
  return $difference;
}

PHP Compare two multidimensional arrays

Assuming that $guestArr is your guest array and $secondArr is your second array, the solution would be like this:

foreach($secondArr as $key => $arr){
    if(!in_array($arr['guest_allow'], $guestArr)){
        unset($secondArr[$key]);
    }
}

// display $secondArr array
var_dump($secondArr);

Here's the live demo.

Compare multidimensional array with another array in PHP and get the values from the multidimensional array

For your example data, you could use array_reduce and use in_array to check if the tag is present in $compare_array

If you must make a variable with the name from the $compare_array and append the value to the variable you might use extract with a flag that suits your expectations.

The value is not present in all the example data so you might also check if that exists.

$compare_array = array('DOCUMENT', 'SENDERID', 'SENDERSHORTNAME', 'RECIPIENTID');
$result = array_reduce($arrays, function($carry, $item) use ($compare_array) {
    if(isset($item["value"]) && in_array($item["tag"], $compare_array, true)) {
        $carry[$item["tag"]] = $item["value"];
    }
    return $carry;
});
extract($result, EXTR_OVERWRITE);

echo $SENDERID;
echo $RECIPIENTID;

Demo

Compare two multidimensional array and replace values based on matching keys

This can be a one-character change:

foreach ($array1 as $defArr)

goes to

foreach ($array1 as &$defArr)
#                   ^

The & reference operator points to the original sub array in the foreach loop context rather than a temporary variable.

However, it's a bit safer to use the index explicitly:

foreach ($array1 as $i => $defArr) {
    foreach ($array2 as $j => $dayArr) {
        if ($dayArr['_id'] == $defArr['_id']) {
            $array1[$i]['M'] = $array2[$j]['M'];
            $array1[$i]['F'] = $array2[$j]['F'];
        }
    }
}

If speed is important or $array2 is large, the time complexity of your algorithm is O(n * m). I recommend hashing $array2 for fast lookups as follows (O(n)):

$lookup = array_reduce($array2, function ($a, $e) {
    $a[$e['_id']] = $e;
    return $a;
});

foreach ($array1 as $i => $e) {
    if (array_key_exists($e['_id'], $lookup)) {
        $array1[$i]['M'] = $lookup[$e['_id']]['M'];
        $array1[$i]['F'] = $lookup[$e['_id']]['F'];
    }
}

Try it!

multidimensional array difference php

Please check if I understand you correctly then this code snippet can help to you solve your problem. I have tested it for your specified problem only. if there are other testcases for which you want to run this, you can tell me to adjust the code.

$a1 = array(
    'a1' => array('a_name' => 'aaa', 'a_value' => 'aaaaa'),
    'b1' => array('b_name' => 'bbb', 'b_value' => 'bbbbbb'),
    'c1' => array('c_name' => 'ccc', 'c_value' => 'cccccc')
);

$a2 = array(
    'b1' => array('b_name' => 'zzzzz'),
);

$result = check_diff_multi($a1, $a2);
print '<pre>';
print_r($result);
print '</pre>';

function check_diff_multi($array1, $array2){
    $result = array();
    foreach($array1 as $key => $val) {
         if(isset($array2[$key])){
           if(is_array($val) && $array2[$key]){
               $result[$key] = check_diff_multi($val, $array2[$key]);
           }
       } else {
           $result[$key] = $val;
       }
    }

    return $result;
}

EDIT: added tweak to code.

Compare multidimensional arrays with array_diff

You could use array_udiff.

If will filter the first array, by comparing its elements to the elements of other arrays passed to array_udiff using the given callback. When the callback returns 0 for a pair, that element is removed from the result.

$result = array_udiff($arr2, $arr1, function ($a, $b) {
    return strcmp($a['email'], $b['email']);
});

Compare two multidimensional arrays then create array of only unique

I would just do a nested foreach loop. I don't know which programming language You're using, but assuming that it's PHP ($):

$tmpArray = array();

foreach($newData as $data1) {

  $duplicate = false;
  foreach($oldData as $data2) {
    if($data1['id'] === $data2['id'] && $data1['name'] === $data2['name'] && $data1['sex'] === $data2['sex']) $duplicate = true;
  }

  if($duplicate === false) $tmpArray[] = $data1;
}

You then have the desired array in the $tmpArray variable. You can make of course $newData = $tmpArray; afterwards.

PHP compare two dimension array

foreach($array1 as $k1 => $arrays) {
    foreach($arrays as $k2 => $val) {

        if($array2[$k1][$k2] == $val) {
            // $array1[$k1][$k2] is equal to $array2[$k1][$k2]
        }
    }
} // end of foreach

The foreach($a as $k => $v) syntax does the same thing as foreach($a as $v), except that it also puts the key associated with the value into $k.

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