foreach 给我错误的结果

Question

So, i have 2 multi dimensional arrays, i'm rendering both arrays through foreach loop and i have 3 condition's in nested foreach

1- when id match from both arrays then a new array assign to empty array

2- when id not match from array 1 with id array 2 then a new array assign to empty array

3- when id not match from array 2 with array 1 then do the same

i have 19 arrays in array 1 and same in array 2 but it giving me 361 results in return any help will be appreciated

$allProducts = array();

foreach ($shopifyProducts as $row)
{
    foreach ($db_Products as $subRow)
    {

        if ($row['id'] == $subRow['product_id'])
        {
            $allProducts[] = array('id' => $row['id'], 'status' => 'db+shopify');                   
        }

        else if ($row['id'] != $subRow['product_id'])
        {
            $allProducts[] = array('id' => $row['id'] ,'status' => 'not exist in db');              
        }

        else if ($subRow['product_id'] != $row['id'])
        {
            $allProducts = array('id' => $subRow['product_id'] , 'status' => 'not exist at shopify');                    
        }

    }
} 

Answer 1

This code first creates 2 new arrays indexed by the id using array_column() , these can then be used in two loops using isset() which is a lot quicker than using in_array each time.

The first loop checks for in both and in shopify but not the database, the second loop checks for in the database but not shopify...

$newArray1 = array_column($array1, null, "id");
$newArray2 = array_column($array2, null, "id");

$allProducts = array();
foreach  ( $array1 as $row )    {
    if ( isset ( $newArray2[$row['id']]) )  {
        $allProducts[] = array('id' => $row['id'], 'status' => 'db+shopify');
    }
    else    {
        $allProducts[] = array('id' => $row['id'] ,'status' => 'not exist in db'); 
    }
}

foreach  ( $array2 as $row )    {
    if ( !isset ( $newArray1[$row['id']]) )  {
        $allProducts[] = array('id' => $row['id'] ,'status' => 'not exist at shopify');
    }
}