PHP convert nested array to single array while concatenating keys?

Question

Here is an example array:

 $foo = array(
           \'employer\' => array(
                    \'name\' => \'Foobar Inc\',
                    \'phone\         


        

Answer 1

/**
 * Flatten a multi-dimensional array or a nested object, constructing concatenated keys for
 *    nested elements.
 * @param array or object $array - the array or object to be flattened
 * @param array or string $key_path - current parent keys path.
 *    Pass this parameter as string if you need to set a common prefix for all keys 
 * @param string $level_separator - keys concatenation glue
 * @param array $flat - resulting flattened array (omit this parameter when calling the function)
 * @return single-dimensional array with all array keys as concatenated keys of elements' 
 *    paths through the data structure
 */
 function flattenArray($array, &$key_path = array(), $level_separator = '.', &$flat = array())
 {
      if(!is_array($key_path))
      {
           // sanitize key_path
           $key_path = array((string)$key_path);
       }
       foreach($array as $key => $value)
       {
            // push current key to path
            array_push($key_path, $key);

            if(is_array($value) || is_object($value))
            {
                 // next level recursion
                 $flat = array_merge($flat, flattenArray($value, $key_path, $level_separator, $flat));
             }
             else
             {
                  // write the value directly
                  $flat[implode($level_separator, $key_path)] = $value;
              }

              // remove used key
              array_pop($key_path);
        }

        return $flat;
  }