在一个经常使用的约定中，任何以下划线开始命名的类都表示没有相应标记的结构。

In one convention that's often used, any class that's named with an initial underscore represents a structure that does not have a corresponding tag.

youdao

所以就没有必要再用下划线表示单词起始了。

Thus there is no need to do so with an underscore character.

youdao

所以就没有必要再用下划线表示单词起始了。

Thus there is no need to do so with an underscore character.

youdao