Optional arguments could be added after the text string to specify the comment introducer, the character used as the "box," and the width of the comment.
可选参数可以添加在文本字符串之后，用来指定评论人，用作 “框” 的字符，以及评论的宽度。
2
If the optional start is specified, it indicates the character position in the source-string at which the search is to begin.
如果指定了可选的起始位置，则表明它是源字符串中开始进行搜索的字符位置。
3
Optional parameters may include information such as character set encoding or language.