今天学习golang，使用 map 时，报错了: assignment to nil map。

assignment to nil map

报错的代码如下所示:

 func (service *StoreService) GetManyByPage(pageCondition PageConditionDTO) (map[string]interface{}, error) {
	var returnMap map[string]interface{}
	var rowList []map[string]interface{}
	whereCondition := map[string]interface{}{"is_del": 0, "is_active": 1}
	selectedFields := []string{"id", " ctime ", "mtime", "priority", "is_active", "name", "address"}
	rowStartIndex := pageCondition.PageIndex * pageCondition.RowCountPerPage

	// Get rows
	err := service.DB.Model(&StoreEntity{}).Select(selectedFields).Where(whereCondition).Limit(pageCondition.RowCountPerPage).Offset(rowStartIndex).Order("mtime DESC, id DESC").Find(&rowList).Error
	if err != nil {
		return returnMap, err
	}

	// Get row count
	rowCount, err := service.getRowCount(whereCondition)
	if err !=  nil  {
		return returnMap, err
	}

	returnMap["pageIndex"] = pageCondition.PageIndex
	returnMap["pageCount"] = utils.CalPageCount(rowCount, int64(pageCondition.RowCountPerPage))
	returnMap["rowCount"] = rowCount
	returnMap["rowCountPerPage"] = pageCondition.RowCountPerPage
	returnMap["rows"] = rowList
	returnMap["rowStartIndex"] = rowStartIndex
	return returnMap, nil
}  

导致错误的就是这一句:

 var returnMap map[string]interface{}  

改为如下代码即可

 returnMap := map[string]interface{}{}  

或者

 var returnMap = make(map[string]interface{})