merge all values of keys in array php

Question

Don't know this question is asked before or not, cannot find after lot of searching.

My array looks like this,

array(3) {
  [0]=>
  array(2) {
    [0]=>
    array(1) {
      ["userId"]=>
      string(3) "421"
    }
    [1]=>
    array(1) {
      ["userId"]=>
      string(3) "329"
    }
  }
  [1]=>
  array(1) {
    [0]=>
    array(1) {
      ["userId"]=>
      string(3) "329"
    }
  }
  [4]=>
  array(2) {
    [0]=>
    array(1) {
      ["userId"]=>
      string(3) "329"
    }
    [1]=>
    array(1) {
      ["userId"]=>
      string(3) "421"
    }
  }
}

What I want is,

array(1) {
  [0]=>
  array(5) {
    [0]=>
    array(1) {
      ["userId"]=>
      string(3) "421"
    }
    [1]=>
    array(1) {
      ["userId"]=>
      string(3) "329"
    }
    [2]=>
    array(1) {
      ["userId"]=>
      string(3) "329"
    }
    [3]=>
    array(1) {
      ["userId"]=>
      string(3) "329"
    }
    [4]=>
    array(1) {
      ["userId"]=>
      string(3) "421"
    }
  }
}

I have tried with array_merge, array_combine and a lot of foreach() loops. But didn't get luck for desired output.

Don't know how to do this. Please help.

Answer 1

You can flatten your array like this:

$arr = array(array(['user' => 1], ['user' => 2]), ['user' => 3]);
$iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($arr));
foreach($iterator as $val) {
  $flattened_arr[0][] = $val;
}
var_dump($flattened_arr);

UPDATE: If you don't want to use RecursiveIteratorIterator, the you can also do it like this using array_walk_recursive():

$non_flat_arr = array(array(['user' => 1], ['user' => 2]), ['user' => 3]);
$objTmp = (object) array('flat_arr' => array());
array_walk_recursive($non_flat_arr, create_function('&$v, $k, &$t', '$t->flat_arr[] = $v;'), $objTmp);
var_dump([ 0 => $objTmp->flat_arr]);

This will give you the output as:

array:1 [
  0 => array:3 [
    0 => 1
    1 => 2
    2 => 3
  ]
]

Hope this helps!