CODEWITHSUNDEEP
phparraysmultidimensional-arraymergegrouping
DonOfDen
DonOfDen

Reputation: 4108

Combine two arrays into a single array based on a common column value

I am trying to combine two arrays while respecting their shared value.

$array1 = array(
    array("id" => "1","name"=>"John"),
    array("id" => "2","name"=>"Peter"),
    array("id" => "3","name"=>"Tom"),
    array("id" => "12","name"=>"Astro")
);

$array2 = array(
    array("id" => "1","second_name"=>"Lim"),
    array("id" => "2","second_name"=>"Parker"),
    array("id" => "3","second_name"=>"PHP")
);

My expected output:

$result = array(
    array("id" => "1","name"=>"John","second_name"=>"Lim"),
    array("id" => "2","name"=>"Peter","second_name"=>"Parker"),
    array("id" => "3","name"=>"Tom","second_name"=>"PHP"),
    array("id" => "12","name"=>"Astro")
);

I have made a try by

$arraycomb = array_unique(array_merge($array1,$array2), SORT_REGULAR);

My output is:

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => John
        )

    [1] => Array
        (
            [id] => 2
            [name] => Peter
        )

    [2] => Array
        (
            [id] => 3
            [name] => Tom
        )

    [3] => Array
        (
            [id] => 12
            [name] => Astro
        )

    [4] => Array
        (
            [id] => 1
            [second_name] => Lim
        )

    [5] => Array
        (
            [id] => 2
            [second_name] => Parker
        )

    [6] => Array
        (
            [id] => 3
            [second_name] => PHP
        )

)

How can I combine the key value inside same array? or how can I bring the expected output?

Note: I am trying for value instead of key ref: PHP Array Merge two Arrays on same key

Upvotes: 3

Views: 3737

Answers (3)

mickmackusa
mickmackusa

Reputation: 48073

Assign temporary first level keys to your first array to aid in identifying rows. Then loop the second array and append the desired column value to the appropriate group. Re-index the array after looping with array_values().

Code: (Demo)

$result = array_column($array1, null, 'id');
foreach ($array2 as $row) {
    $result[$row['id']]['second_name'] = $row['second_name'];
}
var_export(array_values($result));

This is a more direct approach than brute force scanning arrays with nested loops.

If all ids in the second array exist in the first array, then the following simpler line can be written inside the body of the foreach().

$result[$row['id']] += $row;

Upvotes: 0

Sougata Bose
Sougata Bose

Reputation: 31749

You can use array_map() for this. Try this - 

function modifyArray($a, $b)
{
    if (!empty($a) && !empty($b)) {
        return array_merge($a, $b);
    } else if (!empty($a) && empty($b)) {
        return $a;
    }  else if (empty($a) && !empty($b)) {
        return $b;
    }
}

$new = array_map("modifyArray", $array1, $array2);
var_dump($new);

It will generate the new array will all the values in both arrays.if the first array's element is empty then the second array will be merged and vice-versa.

Upvotes: 3

Kevin
Kevin

Reputation: 41893

Alternatively, you could use a foreach in this case then merge them if they share the same id key

With using reference &

foreach($array1 as &$value1) {
    foreach ($array2 as $value2) {
        if($value1['id'] == $value2['id']) {
            $value1 = array_merge($value1, $value2);
        }
    }
}

echo '<pre>';
print_r($array1);

Upvotes: 5

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