How to flatten array of arrays to array?

Question

Possible Duplicate:
How to “flatten” a multi-dimensional array to simple one in php?
How to Flatten a Multidimensional Array?

if I have this code:

$a = array('a','b',array('c','d'));

I would like to know if there is a function that can convert all inner arrays into their elements so the result would be:

$a = array('a','b','c','d');

So I have only the elements of the inner arrays and not arrays.

Answer 1

How about the following:

<?php 
/** 
 * Flattens an array, or returns FALSE on fail. 
 */ 
function array_flatten($array) { 
  if (!is_array($array)) { 
    return FALSE; 
  } 
  $result = array(); 
  foreach ($array as $key => $value) { 
    if (is_array($value)) { 
      $result = array_merge($result, array_flatten($value)); 
    } 
    else { 
      $result[$key] = $value; 
    } 
  } 
  return $result; 
} 
?>

(found in the comments of http://php.net/manual/en/function.array-values.php)

Regards Max

Answer 2

I found the following example on http://php.net/manual/en/function.array-values.php.

function array_flatten($array) {
  if (!is_array($array)) {
    return FALSE;
  }
  $result = array();
  foreach ($array as $key => $value) {
    if (is_array($value)) {
      $result = array_merge($result, array_flatten($value));
    }
    else {
      $result[$key] = $value;
    }
  }
  return $result;
}