?'`' shows the following: "Single and double quotes delimit character constants. They can be used interchangeably but double quotes are *preferred* (and character constants are printed using double quotes), so single quotes are normally only used to delimit character constants containing double quotes."
It is not clear to me why double quote is preferred (I don't think that "character constants are printed using double quotes" should be the reason, in the sense that single quote can be used for printing if we want to do so). It seems that double quote and single quote can be used interchangeably, except that "Single quotes need to be escaped by backslash in single-quoted strings, and double quotes in double-quoted strings." Could somebody why double quote is preferred? ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
