Compare two arrays and return the difference php

To implement a function similar to PHP’s array_diff without using built-in array functions, you can manually compare the values of two arrays. Here’s an example:

<?php

function customArrayDiff($array1, $array2) {
    $difference = []; // Initialize an empty array to store differences.

    foreach ($array1 as $value) {
        // Check if the value is not in the second array.
        $found = false;
        foreach ($array2 as $checkValue) {
            if ($value === $checkValue) {
                $found = true;
                break;
            }
        }

        // If not found, add it to the difference array.
        if (!$found) {
            $difference[] = $value;
        }
    }

    return $difference;
}

// Example usage
$array1 = [1, 2, 3, 4];
$array2 = [2, 4, 6];
$result = customArrayDiff($array1, $array2);

// Output the result
print_r($result);
?>

Output:

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

Explanation:

1. Initialize an Empty Array: Start with an empty array $difference to store the values that are in $array1 but not in $array2.
2. Outer Loop: Loop through each element in $array1.
3. Inner Loop: For each element in $array1, loop through $array2 to check if the current element exists in $array2.
4. Flag for Match: Use a boolean flag ($found) to track if the value exists in $array2. If found, stop the inner loop.
5. Add Unique Values: If the value is not found in $array2, add it to the $difference array.
6. Return the Difference Array: After the loop, return the $difference array.

Keep Learning 🙂