当用户发送一个空文件或键入无效的文件名时，菱形操作符返回未初始化定义的值，使。

When a user sends an empty file or enters an invalid file name, the diamond operator returns the uninitialized defined value, causing a crash of the.

youdao

当用户发送一个空文件或键入无效的文件名时，菱形操作符返回未初始化定义的值，使。

When a user sends an empty file or enters an invalid file name, the diamond operator returns the uninitialized defined value, causing a crash of the.

youdao