PHP版本低于5.5无法使用array_column

public function array_column($input, $columnKey, $indexKey = NULL)
{
$columnKeyIsNumber = (is_numeric($columnKey)) ? TRUE : FALSE;
$indexKeyIsNull = (is_null($indexKey)) ? TRUE : FALSE;
$indexKeyIsNumber = (is_numeric($indexKey)) ? TRUE : FALSE;
$result = array();

foreach ((array)$input AS $key => $row)
{
if ($columnKeyIsNumber)
{
$tmp = array_slice($row, $columnKey, 1);
$tmp = (is_array($tmp) && !empty($tmp)) ? current($tmp) : NULL;
}
else
{
$tmp = isset($row->$columnKey) ? $row->$columnKey : NULL;
}
if ( ! $indexKeyIsNull)
{
if ($indexKeyIsNumber)
{
$key = array_slice($row, $indexKey, 1);
$key = (is_array($key) && ! empty($key)) ? current($key) : NULL;
$key = is_null($key) ? 0 : $key;
}
else
{
$key = isset($row->$indexKey) ? $row->$indexKey : 0;
}
}

$result[$key] = $tmp;
}

return $result;
}