PHP-从多维数组的键中获取价值

Question

Here is my array

$myArray = Array(
[63145] => Array
    (
        [id] => 63145
        [name] => banana
        [type] => fruit
    )

[244340] => Array
    (
        [id] => 244340
        [name] => apple
        [type] => fruit
    )

[253925] => Array
    (
        [id] => 253925
        [name] => portato
        [type] => vegetable
    )

[233094] => Array
    (
        [id] => 233094
        [name] => carrot
        [type] => vegetable
    ));

How do i loop through this and pull out the ids of all fruits, so i kan use them in another foreach loop?

• maybe with a If statement, so that if(type == fruit) use the ids in the foreach loop.

I have tried to look through other questions but I can't figure out how to convert the answers to my array (I know I'm a noob)..

Answer 1

The naïve:

$fruitIds = [];
foreach ($myArray as $item) {
    if ($item['type'] == 'fruit') {
        $fruitIds[] = $item['id'];
    }
}

The functional:

$fruitIds = array_column(
    array_filter($myArray, function (array $i) { return $i['type'] == 'fruit'; }),
    'id'
);

The more efficient functional:

$fruitIds = array_reduce($myArray, function (array $ids, array $i) {
    return array_merge($ids, $i['type'] == 'fruit' ? [$i['id']] : []);
}, []);

Answer 2

You can do this using PHP's array_column and array_filter :

$fruit_ids = array_column(array_filter($arr, function($item, $index) {
  return $item['type'] == 'fruit';
}), 'id');

But also your array keys seem to be the same as your id values on the child arrays, so you could mix array_filter with array_keys :

$fruit_ids = array_keys(array_filter($arr, function($item, $index) {
  return $item['type'] == 'fruit';
}));