在php中根据键的值合并数组

Question

I've this array:

Array
(
    [0] => Array
        (
            [id] => 99
            [fruit] => Apple
            [color] => Green
        )
    [1] => Array
        (
            [id] => 99
            [fruit] => Apple
            [color] => Red
        )
    [2] => Array
        (
            [id] => 555
            [fruit] => Banada
            [color] => Yellow
        )
)

I need to create a new array from this one by merging item by id.

So the final output is the following:

Array
(
    [99] => Array
        (
            [id] => 99
            [fruit] => Apple
            [color] => Green
        ),
        (
            [id] => 99
            [fruit] => Apple
            [color] => Red
        )
    [555] => Array
        (
            [id] => 555
            [fruit] => Banada
            [color] => Yellow
        )
)

Thanks.

Answer 1

You should create a new array to hold the results and iterate over the input, adding every element to the new array. Notice how PHP creates the subarrays automatically.

$output = array();
foreach($input as $fruit){
    $output[$fruit['id']][] = $fruit;
}

Try it online!