To compare two arrays while considering duplicate value

Question

i have two arrays

$array1 = array(1, 2,  2, 3);
$array2 = array( 1, 2,  3,4);

and when did :

var_dump(array_diff($array1,         


        

Answer 1

While it may be less elegant, the simple way to do this is with a for loop:

$diff_array = array();
for ($i = 0; ($i < count($array1)) and ($i < count($array2)); $i++)
{
   if ($array1[$i] !== $array2[$i]) { $diff_array[$i] = $array1[$i]; }
}

Answer 2

Try this

$array1 = array(1, 2, 2, 3, 4, 5, 5, 7);
$array2 = array(1, 2, 4, 6, 3, 3, 5);
$diff = array_filter($array1, 
  function ($val) use (&$array2) { 
    $key = array_search($val, $array2);
    if ( $key === false ) return true;
    unset($array2[$key]);
    return false;
  }
);
print_r($diff);
// Array ( [2] => 2 [6] => 5 [7] => 7 )

Answer 3

This will get you the desired result:

$array1 = array(1, 2,  2, 3);
$array2 = array( 1, 2,  3,4);

$countArray1 = array_count_values($array1);
$countArray2 = array_count_values($array2);

foreach($countArray1 as $value=>$count) {
    if($count > 1) $dupArray[] = $value;
}

foreach($countArray2 as $value=>$count) {
    if($count > 1) $dupArray[] = $value;
}

print_r($dupArray);

Result

Array
(
    [0] => 2
)

Explanation

Using array_count_values will count all the values of an array, which would look like:

Array
(
    [1] => 1
    [2] => 2
    [3] => 1
)

Array
(
    [1] => 1
    [2] => 1
    [3] => 1
    [4] => 1
)

We then iterate through each array_count_values to locate values that occur more than once. This will work when you have more than one set of duplicate values:

$array1 = array(1, 2,  2, 3);
$array2 = array( 1, 2,  3, 4, 3);

Result

Array
(
    [0] => 2
    [1] => 3
)

Answer 4

If you want to count number of duplicate element from same array as well as from multiple arrays, please use below code,

<?php
    $array1 = array(1,2,2,3,7);
    $array2 = array(1,2,3,4);
    $diff_array = array();

    $diff_array1 = array_count_values($array1);
    $diff_array2 = array_count_values($array2);

    $a = array_keys($diff_array1);
    $b = array_keys($diff_array2);

    for($i=0;$i<count($a);$i++)
    {
        if($a[$i] == $b[$i])
        {
            $x = $a[$i];
            $y = $b[$i];
            $diff_array1[$x] += $diff_array2[$y];
        }
    } 
    $diff_array1=array_diff($diff_array1, array('1'));
    echo '<pre>';
    print_r($diff_array1);
?>