从动态主数组创建子数组...基于类似的密钥对

Question

I have a dynamic array.I have shown one instance of that array here.though It is not fixed how many keys are present

Array
(
    [lowest] => 1200
    [highest] => 139900
    [cat_0] => Womens Clothing
    [cat_1] => Smart Phones
    [cat_2] => Mens Clothing
    [cat_3] => Electronics
    [chil_cat_0] => 18
    [chil_cat_1] => 12
    [chil_cat_2] => 7
    [chil_cat_3] => 11
    [chil_cat_4] => 17
    [keyword] => 
)

For this array, I want to create sub array..like.

Array
(
    [cat_0] => Womens Clothing
    [cat_1] => Smart Phones
    [cat_2] => Mens Clothing
    [cat_3] => Electronics
)

Note: Based on similar keys.I have to break my main array to sub array

However, the main array could have any number of similar rows.

Please help me out.

Answer 1

You could use array_filter() to keep only values that match with keys you want :

$out = array_filter($array, function($key){
    // Keep only keys that begins by 'cat_'
    return substr($key, 0, 4) == 'cat_' ; 
    // or
    return preg_match('~^cat_[\d]+~',$key) ; // Use cat_ + number
}, ARRAY_FILTER_USE_KEY);
print_r($out);

Outputs :

Array
(
    [cat_0] => Womens Clothing
    [cat_1] => Smart Phones
    [cat_2] => Mens Clothing
    [cat_3] => Electronics
)