PHP多维关联数组-如何获取键列表？

Question

Here is an example of my data:

[204] => Array
    (
        [1] => Array
            (
                [leads] => 9
            )

        [2] => Array
            (
                [leads] => 15
            )

    )

[200] => Array
    (
        [1] => Array
            (
                [leads] => 7
            )

        [2] => Array
            (
                [leads] => 16
            )

        [3] => Array
            (
                [leads] => 5
            )

    )

I am at the stage where I trying to output the array data into a table but how do I set up the table headers dynamically so that the columns will be 1 | 2 | 3 1 | 2 | 3 1 | 2 | 3 , even if some subsets don't have an array of that type?

The array is constructed from the results of a database query like so:

$dailytotals[$store][$campaigntypeid] = array('leads'=> $leads);

I tried a for each but just realised that it wouldn't work since not all subsets have all columns.

Is there a way to get what I am trying to find?

Answer 1

Try this

$columns = array();
foreach ($your_array as $key=> $arr) {
  $columns = array_unique(array_merge($columns, array_keys($arr)));
}

Another way

$columns = array_reduce($your_array, 
  function ($r, $val) { 
    return array_unique(array_merge($r, array_keys($val))); 
  }, 
  array()
);