static function init(&$arr, $key, $default = null) 
    {
        if (! isset($arr[$key])) {
            $arr[$key] = $default;
        }
        return $arr[$key];
    }
static function init(&$arr, $key, $default = null) 
    {
        if (! isset($arr[$key])) {
            $arr[$key] = $default;
        }
        return $arr[$key];
    }
static function init ( & $ arr , $ key , $ default = null ) { if ( ! isset ( $ arr [ $ key ] ) ) { $ arr [ $ key ] = $ default ; } return $ arr [ $ key ] ; }
Init an key value inside an array

@param array  $arr     The array
@param string $key     The key
@param mixed  $default The default value to fill if key is not found

@return array The array
Init an key value inside an array