Is it possible to combine arrays?

Question

Is it possible to merge the contents of all existing arrays, if the key is already in use - then nothing, and if not - then it must be added from other arrays, but with an empty value

  array(3) {
      [0]=>
            array(4) {
              ["attributes_3_ru-ru"] => "10"
              ["attributes_3_en-gb"] => "100"
              ["attributes_4_en-gb"] => "2222"
              ["attributes_4_ru-ru"] => ""
            }
      [1]=>
            array(2) {
              ["attributes_6_ru-ru"] => "10"
              ["attributes_6_en-gb"] => "100"
            }
        }
      [2]=>
            array(2) {
              ["attributes_4_ru-ru"] => "10"
              ["attributes_4_en-gb"] => "100"
            }
            ...n
    }

output is something like this

array(3) {
  [0]=>
        array(4) {
          ["attributes_3_ru-ru"] => "10"
          ["attributes_3_en-gb"] => "100"
          ["attributes_4_en-gb"] => "2222"
          ["attributes_4_ru-ru"] => ""
          ["attributes_6_ru-ru"] => ""
          ["attributes_6_en-gb"] => ""
        }
  [1]=>
        array(2) {
          ["attributes_6_ru-ru"] => "10"
          ["attributes_6_en-gb"] => "100"
          ["attributes_3_ru-ru"] => ""
          ["attributes_3_en-gb"] => ""
          ["attributes_4_en-gb"] => ""
          ["attributes_4_ru-ru"] => ""
        }
    }
  [2]=>
        array(2) {
          ["attributes_4_ru-ru"] => "10"
          ["attributes_4_en-gb"] => "100"
          ["attributes_6_ru-ru"] => ""
          ["attributes_6_en-gb"] => ""
          ["attributes_3_ru-ru"] => ""
          ["attributes_3_en-gb"] => ""
        }
        ...n
    }

That duplicate does not address this question at all. It merges multiple arrays into a single array. — Don't Panic, May 16 '18 at 19:22
it addresses it, just loop over your array of arrays and merge your arrays as required. — Andrew, May 16 '18 at 19:37
@Andrew I apologize. Saying it doesn't address it at all was inaccurate, or at least an overstatement. I should have said, I think it's only part of the answer, and not a big enough part to be an appropriate duplicate. — Don't Panic, May 16 '18 at 19:45

score 2 · Answer 1 · answered May 16 '18 at 19:14

2

I would do it like this. First, collect all the keys and create a "template" array with from that with blank values.

$merged = array_merge(...$arrays);
$template = array_fill_keys(array_keys($merged), '');

Then map that over the original array of arrays and merge each entry with the template.

$result = array_map(function($entry) use ($template) {
    return array_merge($template, $entry);
}, $arrays);

answered May 16 '18 at 19:14

Don't Panic

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,what is array_fill_keys and when we have to use it? – jvk May 16 '18 at 19:20
@whoami array_fill_keys takes an array and a value, and creates a new array using the input array as keys, where each key has the same single value. http://php.net/manual/en/function.array-fill-keys.php – Don't Panic May 16 '18 at 19:23

Luke · Answer 2 · 2018-05-16T19:21:48.303

You should use array_merge() for this.

$megaArray = array_merge($array1, $array2, $array3);

Or if I'm oversimplifying your use case and for some reason you need to append data to $array3 you could use foreach() and in_array() instead. Something along the lines of the following (not tested).

foreach($array1 as $key => $value){
    if(!in_array($key, $array3)){
        $array3[$key] = $value;
  }
  else{
        if($array3[$key] === ""){ // if the current array3 iteration's value is blank, use the new one
            $array3[$key] = $value;
        }
  }
}

Is it possible to combine arrays?

2 Answers2