I want a function that will return TRUE or FALSE based on if a given key exists in a multidimensional array in PHP.
I haven’t been able to figure out a recursive function to perform this action.
A sample of what this could do:
JavaScript
x
$array = array(
'key 1' => array(
'key 1.1' => array()
'key 1.2' => array()
),
'key 2' => array(
'key 2.1' => array(
'key 2.1.1' => array()
)
'key 2.2' => array()
)
);
multi_array_key_exists('key 1', $array); // return TRUE
multi_array_key_exists('key 2.1.1', $array); // return TRUE
multi_array_key_exists('key 3', $array); // return FALSE
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Answer
This is where a recursive function comes in handy.
JavaScript
function multi_array_key_exists($key, array $array): bool
{
if (array_key_exists($key, $array)) {
return true;
} else {
foreach ($array as $nested) {
if (is_array($nested) && multi_array_key_exists($key, $nested))
return true;
}
}
return false;
}
Note that this can take some time (in long nested arrays), it might be better to flatten first, since you are only interested in whether the key exists or not.