Find a key exists in the sub keys of an array?

Question

How can I check if a key exists in the sub keys of an array? And if that key of the item is found then return that item?

For instance, I have this array,

Array
(
    [0] => Array
        (
            [a] => Array
                (
                    [quantity_request] => 1
                    [time_created] => 1339688613
                    [variant] => Array
                        (
                        )

                )

        )

    [1] => Array
        (
            [b] => Array
                (
                    [quantity_request] => 1
                    [time_created] => 1339688631
                    [variant] => Array
                        (
                        )

                )

        )

    [2] => Array
        (
            [c] => Array
                (
                    [quantity_request] => 1
                    [time_created] => 1339688959
                    [variant] => Array
                        (
                        )

                )

        )

)

I want to find key 'b' and return everything under it, like this is what I am after,

[b] => Array
                (
                    [quantity_request] => 1
                    [time_created] => 1339688631
                    [variant] => Array
                        (
                        )

                )

I try with this, but nothing returns,

if (array_key_exists('b', $this->content)) {
                echo "The 'b' element is in the array";

}

Any ideas?

score 1 · Accepted Answer · answered Jun 14 '12 at 16:06

1

function get_letter($letter){
    foreach($this->content as $v){
        if(array_key_exists($letter, $v) {
            return $v[$letter];
        }
    }
    return false;
}

$array = get_letter('a');

answered Jun 14 '12 at 16:06

472084

17,666
10
63
81

score 0 · Answer 2 · answered Jun 14 '12 at 16:07

0

Couldn't you just loop over the outer array, checking each array inside for the key?

foreach($this->content as $arr) {
  if(array_key_exists('b', $arr) {
    echo "Found it";
  }
}

answered Jun 14 '12 at 16:07

Mads Ohm Larsen

3,315
3
20
22

score 0 · Answer 3 · answered Jun 14 '12 at 16:08

0

foreach() the root Array, then array_key_exists().

foreach ($array as $key => $value) {
    if (array_key_exists('b', $array[$key])) {
        return $array[$key]['b'];
    }
}

answered Jun 14 '12 at 16:08

HBv6

3,487
4
30
43

score 0 · Answer 4 · answered Jun 14 '12 at 16:51

0

I wouldn't actually use this because it's not clear code, but, it's a cool one liner for php 5.4

$val = call_user_func_array('array_merge', $array)['b'];

answered Jun 14 '12 at 16:51

goat

31,486
7
73
96

score 0 · Answer 5 · answered Apr 27 '22 at 23:21

0

Nice another variant:

array_merge(... $array)['b']

answered Apr 27 '22 at 23:21

dikirill

1,873
1
19
21

Find a key exists in the sub keys of an array?

5 Answers5

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