Comment/uncomment current line/selection

`Ctrl` + `Shift` + `C`

All hotkeys for RStudio (Windows)

Console Move cursor to console	`Ctrl` + `2`
Console Clean console	`Ctrl` + `L`
Console Move cursor to beginning of line	`Home`
Console Move cursor to end of line	`End`
Console Navigate command history	`Up` / `Down`
Console Popup command history	`Ctrl` + `Up`
Console Interrupt currently executing command	`Esc`
Console Change working directory	`Ctrl` + `Shift` + `H`
Source Goto file/function	`Ctrl` + `.`
Source Move cursor to source editor	`Ctrl` + `1`
Source New document (except on chrome/windows)	`Ctrl` + `Shift` + `N`
Source New document (Chrome only)	`Ctrl` + `Alt` + `Shift` + `N`
Source Open document	`Ctrl` + `O`
Source Save active document	`Ctrl` + `S`
Source Close active document (except on Chrome)	`Ctrl` + `W`
Source Close active document (Chrome only)	`Ctrl` + `Alt` + `W`
Source Close all open documents	`Ctrl` + `Shift` + `W`
Source Preview HTML (markdown and HTML)	`Ctrl` + `Shift` + `K`
Source Compile notebook/compile PDF (TeX and Sweave)	`Ctrl` + `Shift` + `K`
Source Insert chunk (Sweave and Knitr)	`Ctrl` + `Alt` + `I`
Source Insert code section	`Ctrl` + `Shift` + `R`
Source Run current line/selection	`Ctrl` + `Enter`
Source Run current line/selection (retain cursor position)	`Alt` + `Enter`
Source Re-run previous region	`Ctrl` + `Shift` + `P`
Source Run current document	`Ctrl` + `Alt` + `R`
Source Run from document beginning to current line	`Ctrl` + `Alt` + `B`
Source Run from current line to document end	`Ctrl` + `Alt` + `E`
Source Run from current line to document end	`Ctrl` + `Alt` + `F`
Source Run the current code section	`Ctrl` + `Alt` + `T`
Source Run previous sweave/Rmd code	`Ctrl` + `Alt` + `P`
Source Run the current Sweave/Rmd chunk	`Ctrl` + `Alt` + `C`
Source Run the next Sweave/Rmd chunk	`Ctrl` + `Alt` + `N`
Source Source a file	`Ctrl` + `Shift` + `O`
Source Source the current document	`Ctrl` + `Shift` + `S`
Source Source the current document (with echo)	`Ctrl` + `Shift` + `Enter`
Source Fold selected	`Alt` + `L`
Source Unfold selected	`Shift` + `Alt` + `L`
Source Fold all	`Alt` + `O`
Source Unfold all	`Shift` + `Alt` + `O`
Source Go to line	`Shift` + `Alt` + `G`
Source Jump to	`Shift` + `Alt` + `J`
Source Switch to tab	`Ctrl` + `Shift` + `.`
Source Previous tab	`Ctrl` + `F11`
Source Next tab	`Ctrl` + `F12`
Source First tab	`Ctrl` + `Shift` + `F11`
Source Last tab	`Ctrl` + `Shift` + `F12`
Source Navigate back	`Ctrl` + `F9`
Source Navigate forward	`Ctrl` + `F10`
Source Extract function from selection	`Ctrl` + `Alt` + `X`
Source Extract variable from selection	`Ctrl` + `Alt` + `V`
Source Reindent lines	`Ctrl` + `I`
Source Comment/uncomment current line/selection	`Ctrl` + `Shift` + `C`
Source Reflow comment	`Ctrl` + `Shift` + `/`
Source Reformat selection	`Ctrl` + `Shift` + `A`
Source Show diagnostics	`Ctrl` + `Shift` + `Shift` + `P`
Source Move lines Up/Down	`Alt` + `Up/Down`
Source Copy lines Up/Down	`Shift` + `Alt` + `Up/Down`
Source Jump to matching Brace/Paren	`Ctrl` + `P`
Source Expand to matching Brace/Paren	`Ctrl` + `Shift` + `E`
Source Select to matching Brace/Paren	`Ctrl` + `Shift` + `Alt` + `E`
Source Add cursor above current cursor	`Ctrl` + `Alt` + `Up`
Source Add cursor beow current cursor	`Ctrl` + `Alt` + `Down`
Source Move active cursor up	`Ctrl` + `Alt` + `Shift` + `Up`
Source Move Active Cursor Down	`Ctrl` + `Alt` + `Shift` + `Down`
Source Find and replace	`Ctrl` + `F`
Source Find next	`F3`
Source Find previous	`Shift` + `F3`
Source Use selection for find	`Ctrl` + `F3`
Source Replace and find	`Ctrl` + `Shift` + `J`
Source Find in files	`Ctrl` + `Shift` + `F`
Source Check spelling	`F7`
Completions (Console and Source) Attempt completion	`Tab` / `Ctrl` + `Space`
Completions (Console and Source) Navigate candidates	`Up` / `Down`
Completions (Console and Source) Accept selected candidate	`Enter` / `Tab` / `Right`
Completions (Console and Source) Dismiss completion popup	`Esc`
Views Move focus to Source Editor	`Ctrl` + `1`
Views Move focus to Console	`Ctrl` + `2`
Views Move focus to Help	`Ctrl` + `3`
Views Show History	`Ctrl` + `4`
Views Show files	`Ctrl` + `5`
Views Show plots	`Ctrl` + `6`
Views Show packages	`Ctrl` + `7`
Views Show environment	`Ctrl` + `8`
Views Show git/svn	`Ctrl` + `9`
Views Show build	`Ctrl` + `0`
Views Sync editor & pdf preview	`Ctrl` + `F8`
Views Reference	`Alt` + `Shift` + `K`
Build Build and reload	`Ctrl` + `Shift` + `B`
Build Load all (devtools)	`Ctrl` + `Shift` + `L`
Build Test package (desktop)	`Ctrl` + `Shift` + `T`
Build Test package (web)	`Ctrl` + `Alt` + `F7`
Build Check package	`Ctrl` + `Shift` + `E`
Build Document package	`Ctrl` + `Shift` + `D`
Debug Toggle breakpoint	`Shift` + `F9`
Debug Execute next line	`F10`
Debug Step into function	`Shift` + `F4`
Debug Finish function/loop	`Shift` + `F6`
Debug Continue	`Shift` + `F5`
Debug Stop debugging	`Shift` + `F8`
Plots Previous plot	`Ctrl` + `Alt` + `F11`
Plots Next plot	`Ctrl` + `Alt` + `F12`
Git / SVN Diff active source document	`Ctrl` + `Alt` + `D`
Git / SVN Commit changes	`Ctrl` + `Alt` + `M`
Git / SVN Scroll diff view	`Ctrl` + `Up/Down`
Git / SVN Stage/unstage(Git)	`Spacebar`
Git / SVN Stage/unstage and move to next (Git)	`ENter`
Session Quit Session (desktop only)	`Ctrl` + `Q`
Session Restart R Session	`Ctrl` + `Shift` + `F10`
Editing (Console and Source) Undo	`Ctrl` + `Z`
Editing (Console and Source) Redo	`Ctrl` + `Shift` + `Z`
Editing (Console and Source) Cut	`Ctrl` + `X`
Editing (Console and Source) Copy	`Ctrl` + `C`
Editing (Console and Source) Paste	`Ctrl` + `V`
Editing (Console and Source) Select all	`Ctrl` + `A`
Editing (Console and Source) Jump to word	`Ctrl` + `Left/Right`
Editing (Console and Source) Jump to start/end	`Ctrl` + `Home/End` / `Ctrl` + `Up/Down`
Editing (Console and Source) Delete line	`Ctrl` + `D`
Editing (Console and Source) Select	`Shift` + `Arrow`
Editing (Console and Source) Select word	`Ctrl` + `Shift` + `Left/Right`
Editing (Console and Source) Select to line start	`Alt` + `Shift` + `Left`
Editing (Console and Source) Select to line end	`Alt` + `Shift` + `RIght`
Editing (Console and Source) Select page up/down	`Shift` + `Page Up` / `Shift` + `Page down`
Editing (Console and Source) Select page start/end	`Ctrl` + `Shift` + `Home/End`
Editing (Console and Source) Delete word left	`Ctrl` + `Backspace`
Editing (Console and Source) Indent	`Tab`
Editing (Console and Source) Outdent	`Shift` + `Tab`
Editing (Console and Source) Yank line up to cursor	`Ctrl` + `U`
Editing (Console and Source) Yank line after cursor	`Ctrl` + `K`
Editing (Console and Source) Insert currently yanked text	`Ctrl` + `Y`
Editing (Console and Source) Insert assignment operator	`Alt` + `-`
Editing (Console and Source) Insert pipe operator	`Ctrl` + `Shift` + `M`
Editing (Console and Source) Show help for function at cursor	`F1`
Editing (Console and Source) Show source code for function at cursor	`F2`
Editing (Console and Source) Find usages for symbol at cursor (C++)	`Ctrl` + `Alt` + `U`