R: Comment multiple lines

Question

I have two questions:

1: Is there a way in R to mark multiple code lines as a comment? I know that from PHP, where you can do it like this:

code
code

/*
comment only
comment only
comment only
*/

#instead of doing

//comment only
//comment only
//comment only

2. Can I avoid that commented lines appear in the output of RStudio? I only want to see non-commented lines or output.

Thank you!