如何在PHP中重组数组？

I am trying to figure out how to reorganize an array.. I have a multidimensional array(Ill call that original_array) and I would like to take the first array within original_array and set the values as keys in a new array. I also want to take the values of the second array in original_array and make them keys and then set the values of the third array in original_array as the values for those keys.

Here is an example of original_array:

Array ( 
       [id] => Array ( 
                      [0] => 1 
                      [1] => 3 
                     ) 
   [reward] => Array ( 
                      [0] => Movie
                      [1] => Trip
                     ) 
     [cost] => Array ( 
                      [0] => 50 
                      [1] => 200
                     ) 
      )

Basically what I would like to do is look like this:

Array ( 
       [1] => Array ( 
                     [Movie] => 50
                    )
       [3] => Array (
                     [Trip] => 200
                    )
      )

Is there a simple and elegant way to merge these like this? I have spent hours trying to figure this out using array_merge, array_merge_recursive.. etc. And have search SO far and wide for a similar questions, but I haven't found anything that does what I am after.

I was able to correctly combine the 2nd and 3rd arrays in original_array with array_combine. But, I am at a loss as how to combine that result with the 1st array's values in original_array.

Thanks in advance to any help!

There may be some incantation of array_*() merging functions that could produce what you're looking for, but it is far easier to just iterate over the original array's [id] sub-array and use its values to create new sub-array keys in a different output array.

// To hold your output
$output = array();

// Iterate the original array's [id] sub-array
foreach ($original['id'] as $idxkey => $newkey) {
  // Add a sub-array using $newkey to the output array
  $output[$newkey] = array( 
    // Using the index (not value), retrieve the corresponding reward
    // value to use as the new array key
    // and corresponding cost to use as the new subarray value
    $original['reward'][$idxkey] => $original['cost'][$idxkey]
  );
}

Here is a demonstration: https://3v4l.org/2pac3

Well, the dirty way would be just use combine array functions like array_combine with the input:

$new_array = array_combine(
    $array['id'], // parent keys
    // combine chunked combined sub keys :p
    array_chunk(array_combine($array['reward'], $array['cost']), 1, true)
);

This should work for you:

First you can get the keys for the main array into a separate variable with array_shift(), which will just remove the first element from your array, which is the array holding the keys.

Then use array_map() to loop through both of your subArrays and use reward as key with the cost values as value and return it in an array. At the end you just have to array_combine() your keys $keys with the new created array.

Code:

<?php

    $keys = array_shift($arr);

    $result = array_combine($keys, array_map(function($k, $v){
        return [$k => $v];
    }, $arr["reward"], $arr["cost"]));


    print_r($result);

?>

You might wanna take a look at BaseArrayHelper from Yii 2.0 Framework.

Although this file is part of a framework it has only very few dependencies and you should be able to use just this file or parts of it in your code with small modifications.

An example for your use case can be found in the index() method.