undefined operation
常见例句
- Otherwise, the operation is erroneous and its outcome is undefined.
否则的话，这一操作是错误并且它的结果是未定义的。 - When you load content from a URL, the default value is undefined until the load operation has started.
从 URL 加载内容时，直到开始加载操作，才会定义默认值。 - The behavior of this operation is undefined if the specified collection is modified while the operation is in progress.
如果在操作过程中，指定的集合已被修改，则此操作的行为是未定义的。 返回 undefined operation