PHP：在数组中搜索值并显示键

Question

I have array with the structure as below.

Array
(
    [example1] => Array
        (
            [0] => 'banana'
        )

    [example2] => Array
        (
            [0] => 'orange'
            [1] => 'apple'
            [2] => 'plum'
            [3] => 'watermelon'
            [4] => 'pumpkin'
        )

    [example3] => Array
        (
            [0] => 'cherry'
            [1] => 'strawberry'
        )

)

I am trying to display the key name for a sample value.

Eg. looking for a value: ' apple ' - result: ' example2 '

Answer 1

Just iterate thru all the subarrays and return the parent key.

$array = [
    'example1' => ['banana'],
    'example2' => ['orange', 'apple', 'plum', 'watermelon', 'pumpkin'],
    'example3' => ['cherry', 'strawberry']
];

$needle = 'apple';
$result = '';
foreach($array as $parentKey => $child) {
    if(in_array($needle, $child)) {
        $result = $parentKey;
        break;
    }
}

echo $result;

example2

Answer 2

Simply loop your arrays and check if element exists:

function search(string $search, array $source) {
    foreach ($source as $key => $sub) {
        if (in_array($search, $sub)) {
            return $key;
        }
    }
}

search('apple', $source);

Answer 3

that's a good example too, thanks. I built my function on this basis

function CheckArray($my_array,$search) {
$result = array_keys(array_filter($my_array, function ($arr) use ($search) {
return in_array($search, $arr);
}));
if(isset($result[0])){
    return $result[0];
}else{
    return "not find";
}

}