How convert a Multidimensional array into one-dimensional array? [duplicate]

You need iterate first by $array[0], $array[1] and get the value that you need in a foreach loop. See the code:

<?php
$array = Array (
 0 => Array ( 'PRODUCT_ID' => 40 ),
 1 => Array ( 'QUANTITY' => 2 ),
 2 => Array ( 'PIECE_BAG' => 3 ),
 3 => Array ( 'TOTAL_QUANTITY' => 2 ),
 4 => Array ( 'UNIT_PRICE' => 3 ),
 5 => Array ( 'TOTAL_PRICE' => 6 ),
 6 => Array ( 'AVAILABILITY' => 4 ) );

$new_array = array();

for($i = 0; $i < 2; $i++) {
  foreach($array[$i] as $key => $value) {
    $new_array[$key] = $value;
  }  
} 

print_r($new_array);

Output:

Array
(
    [PRODUCT_ID] => 40
    [QUANTITY] => 2
)