Dynamically create multidimensional array - php

Question

I am trying to generate a multidimensional array, with a depth equal to the number of matches found in a regular expression. The array keys to be the string value of each match.
For example:
preg_match('/([A-Z])\-?([0-9])\-?([0-9]{1,3})/i', 'A-1-001', $matches);
Returns:
Array (
[0] => A-1-001
[1] => A
[2] => 1
[3] => 001
)
Which I want to convert to:
$foo = array(
'A' => array(
'1' => array(
'001' => array('some', 'information')
)
)
);
So that I can merge it with another multidimensional array like this:
$bar['A']['1']['001'] = array('some', 'other', 'information');
The process needs to handle any number of matches/dimensions.
Below is my current approach. I'm failing to grasp the concept, because this attempt falls way short of my goal.
$foo = array();
$j = count($matches);
for ($i = 1; $i < $j; $i++) {
$foo[ $matches[$i - 1] ] = $matches[$i];
}
/*
$foo's structure becomes:
Array (
[A-1-001] => A
[A] => 1
[1] => 001
)
*/
It's only swapping array keys, and not creating new children arrays I need.
Any suggestions or solutions would be greatly appreciated. Thanks!

Answer 1

With some PHP-Fu:
$matches = array('A-1-001', 'A', 1, '001');
$info = array('some', 'information');
print_r(tree($matches, $info));
function tree($array, $info){
$max = count($array)-1;
$result = array($array[$max] => $info);
for($i=$max-1;$i>0;$result = array($array[$i--] => $result));
return $result;
}
Output:
Array
(
[A] => Array
(
[1] => Array
(
[001] => Array
(
[0] => some
[1] => information
)
)
)
)

Answer 2

Well this could be done in a couple of ways, use of recursion for example. Now I had an other idea in my head. You flip the array with array_reverse. This way we can build from the back to the front.
And then we can setup everything. So the code would be something as followed
$foo = array();
$reversed = array_reverse($matches);
$some_info_array = array('some', 'information');
foreach($reversed as $key) {
if(empty($foo)) {
$foo[$key] = $some_info_array;
} else {
$foo[$key] = $foo;
}
}
code not tested but should give you a nive idea/start

Answer 3

Given the original array:
$original_array = array( 'A-1-001', 'A', '1', '001' );
You can convert it to the format you described like this:
$new_array[ $original_array[1] ] = array( $original_array[2] => $original_array[3] );
This yields
array(1) {
["A"]=>
array(1) {
[1]=>
string(3) "001"
}
}
You can then assign values to that array as you indicated:
$new_array['A']['1']['001'] = array('some', 'information');

Answer 4

You could use a function like this ... it should cover any depth. Bonus is that you can keep passing the value of $tree to more branches and get a single tree with multiple products.
function arrayToTree($array, &$tree, $addlAttribs){
$node = array_shift($array);
if (count($array)){
// this is a branch
$tree[$node] = array();
return arrayToTree($array, $tree[$node]);
} else {
$tree[$node] = $addlAttribs;
return;
}
}
You would use it like
$t = array();
array_shift($matches); // remove the first match "A-1-001"
arrayToTree($matches, $tree, $productInfo);
print_r($tree);