Get Difference Between Associative Rows of Two 2-Dimensional Arrays

Get difference between associative rows of two 2-dimensional arrays

To check multi-deminsions try something like this:

$pageWithNoChildren = array_map('unserialize',
    array_diff(array_map('serialize', $pageids), array_map('serialize', $parentpage)));

• array_map() runs each sub-array of the main arrays through serialize() which converts each sub-array into a string representation of that sub-array
  
  • the main arrays now have values that are not arrays but string representations of the sub-arrays
• array_diff() now has a one-dimensional array for each of the arrays to compare
• after the difference is returned array_map() runs the array result (differences) through unserialize() to turn the string representations back into sub-arrays

Q.E.D.

Get difference between two multidimensional arrays by comparing rows

You could always start by reading the PHP manual.

For array_diff_assoc (on http://php.net/manual/en/function.array-diff-assoc.php) it is said that this function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using, for example, array_diff_assoc($array1[0], $array2[0]);.

Provided solution in user comments (this does work):

55 dot php at imars dot com
17-Mar-2009 03:09 I've worked on
array_diff_assoc_recursive() mentioned
by chinello at gmail dot com and I
think it might be worth mentioning
here. I wrote a dozen test cases and
it seems to be holding up pretty well.

<?php
// dwarven Differences:
// * Replaced isset() with array_key_exists() to account for keys with null contents

// 55 dot php at imars dot com Differences:
// Key differences:
// * Removed redundant test;
// * Returns false bool on exact match (not zero integer);
// * Use type-precise comparison "!==" instead of loose "!=";
// * Detect when $array2 contains extraneous elements;
// * Returns "before" and "after" instead of only "before" arrays on mismatch.

function array_compare($array1, $array2) {
    $diff = false;
    // Left-to-right
    foreach ($array1 as $key => $value) {
        if (!array_key_exists($key,$array2)) {
            $diff[0][$key] = $value;
        } elseif (is_array($value)) {
             if (!is_array($array2[$key])) {
                    $diff[0][$key] = $value;
                    $diff[1][$key] = $array2[$key];
             } else {
                    $new = array_compare($value, $array2[$key]);
                    if ($new !== false) {
                         if (isset($new[0])) $diff[0][$key] = $new[0];
                         if (isset($new[1])) $diff[1][$key] = $new[1];
                    };
             };
        } elseif ($array2[$key] !== $value) {
             $diff[0][$key] = $value;
             $diff[1][$key] = $array2[$key];
        };
 };
 // Right-to-left
 foreach ($array2 as $key => $value) {
        if (!array_key_exists($key,$array1)) {
             $diff[1][$key] = $value;
        };
        // No direct comparsion because matching keys were compared in the
        // left-to-right loop earlier, recursively.
 };
 return $diff;
};
?>

While comparing associative rows between two 2d arrays, array_diff_assoc() gives the wrong difference

Two values from key => value pairs are considered equal only if (string) $elem1 === (string) $elem2 . In other words a strict check takes place so the string representations must be the same.

http://php.net/manual/en/function.array-diff-assoc.php

The (string) value of any array is "Array". Thus, your call to array_diff_assoc is effectively comparing these two things:

Array ( [0] => "Array" [1] => "Array" ) 
Array ( [0] => "Array" ) 

Since the thing that is different between those two is the [1] key/value pair from the first array, you get that back ([1] => Array( [11] => common set )).

Check if associative multi-dimensional arrays are equal regardless of order of keys in either level

Here's a recursive comparison function

function CompareRecursive($array1, $array2, &$mismatches) {
    foreach ($array1 as $key => $value) {
        if (!isset($array2[$key])) { 
            $mismatches[$key] = [ $value ];
            continue;
        } 

        $value2 = $array2[$key];  
        if (!is_array($value) || !is_array($value2)) {                
            if ($value != $value2) {
                $mismatches[$key] = [
                    $value, $value2
                ];
            }
        } else {
            $mismatches_internal = [];
            CompareRecursive($value, $value2, $mismatches_internal);
            if (!empty($mismatches_internal)) {
                $mismatches[$key] = $mismatches_internal;
            }
        } 
    }
    return empty($mismatches);
}

As an added bonus this keeps track of mismatched entries too, there's a drawback when using this method that it won't work if $array2 has extra elements that $array1 doesn't but you can resolve this by doing:

$isEqual = CompareRecursive($array1,$array2) && CompareRecursive($array2,$array1);

Compare 2-dimensional data sets based on a specified second level value

I would probably iterate through the original arrays and make them 1-dimensional... something like

foreach($array1 as $aV){
    $aTmp1[] = $aV['ITEM'];
}

foreach($array2 as $aV){
    $aTmp2[] = $aV['ITEM'];
}

$new_array = array_diff($aTmp1,$aTmp2);

get the diffrence array from 2 multidimensional arrays

If you're looking at any difference and not just one value:

$result = array_map('unserialize', array_diff(
    array_map('serialize', $array2), array_map('serialize', $array1)));

print_r($result);  

Comparing Changes in Multidimensional Arrays - PHP

//'BEFORE' ARRAY
$arr1 = array( array(1231, 'Name1'), array(1232, 'Name2'), array(1233, 'Name3-Deleted') );

//'AFTER' ARRAY
$arr2 = array( array(1231, 'Name1-Renamed'), array(1232, 'Name2'), array(1230, 'Name4-New') );

// Kudos to AbraCadaver for the following:
$arr1 = array_column($arr1, 1, 0);
$arr2 = array_column($arr2, 1, 0);

$added = array_diff_key($arr2, $arr1);
$deleted = array_diff_key($arr1, $arr2);
$modified = array_diff_key(array_diff($arr2, $arr1), $deleted, $added);

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