Find a value & key in a multidimensional array [duplicate] - php

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Find value and key in multidimensional array
(8 answers)
Closed 9 years ago.
I have 2 arrays, I need to find if one of the values in array one matches one of the values in array two, a multi-dimensional array. I also need to check that the value from array one is in a specific key in array two, the "principal" key as the "authority" key may also hold this value.
here is array one:
Array
(
[0] => 17
[1] => 6
[2] => 3
[3] => 2
)
and array two [actually slightly truncated for readability]:
Array
(
[modAccessResourceGroup] => Array
(
[3] => Array
(
[0] => Array
(
[principal] => 0
[authority] => 9999
[policy] => Array
(
[load] => 1
)
)
[1] => Array
(
[principal] => 2
[authority] => 10
[policy] => Array
(
[add_children] => 1
[create] => 1
[copy] => 1
[delete] => 1
[list] => 1
[load] => 1
[move] => 1
[publish] => 1
[remove] => 1
[save] => 1
[steal_lock] => 1
[undelete] => 1
[unpublish] => 1
[view] => 1
)
)
.... truncated ....
[13] => Array
(
[principal] => 16
[authority] => 9999
[policy] => Array
(
[load] => 1
)
)
)
[8] => Array
(
[0] => Array
(
[principal] => 0
[authority] => 9999
[policy] => Array
(
[load] => 1
)
)
[1] => Array
(
[principal] => 1
[authority] => 9999
[policy] => Array
(
[add_children] => 1
[create] => 1
[copy] => 1
[delete] => 1
[list] => 1
[load] => 1
[move] => 1
[publish] => 1
[remove] => 1
[save] => 1
[steal_lock] => 1
[undelete] => 1
[unpublish] => 1
[view] => 1
)
)
[2] => Array
(
[principal] => 22
[authority] => 9999
[policy] => Array
(
[add_children] => 1
[create] => 1
[copy] => 1
[delete] => 1
[list] => 1
[load] => 1
[move] => 1
[publish] => 1
[remove] => 1
[save] => 1
[steal_lock] => 1
[undelete] => 1
[unpublish] => 1
[view] => 1
)
)
)
)
)
I was using a series of foreach(){foreach(){foreach(){}}} but it seemed very messy and inefficient. Having some trouble getting my head around this. Any ideas?

Answer 1

A recursive function should do the trick:
$values = array(17, 6, 3, 2, 5);
function find($array, &$values) {
foreach ($array as $key => $element) {
if (is_array($element)) {
find($element, $values);
}
elseif ($key == 'principal') {
foreach ($values as $value) {
if ($element == $value) {
echo 'Found' . PHP_EOL;
// Do stuff
}
}
}
}
}
find($array, $values);

Answer 2

Several things come to mind. First, in situations like this, I will usually create a separate array with just the principal values so that I can loop over the first array and just use a simple in_array() check. Secondly, if you don't want to do that, you could do something using the array_walk_recursive() function or some of the recursive examples in array_search() to go through your second array.