This expression also removes all null characters and excess whitespace.

此表达式也会删除所有空字符和过量的空白。

youdao

For instance, you don't need to check whether the data contains null characters because an XML parser will never pass you a null.

例如，不需要检查数据是否包含空字符，因为XML解析器绝不会传送一个空值。

youdao