Comment / uncomment line or selection (add //)

`Ctrl` + `/`

All hotkeys for Eclipse

Managing files and projects Create a new project with Wizard	`Ctrl` + `N`
Managing files and projects Create a new project, file, class, etc.	`Ctrl` + `Alt` + `N`
Managing files and projects . Open project, file, etc.	`Alt` + `F` then `.`
Managing files and projects Open resource file, folder or project	`Ctrl` + `↑ Shift` + `R`
Managing files and projects Show and access file properties	`Alt` + `⤶ Enter`
Running and debugging Step into function	`F5`
Managing files and projects Save currently open file	`Ctrl` + `S`
Managing files and projects Save all open files	`Ctrl` + `↑ Shift` + `S`
Managing files and projects Close currently open file	`Ctrl` + `W`
Managing files and projects Close all files	`Ctrl` + `↑ Shift` + `W`
Editor Jump to the editor window	`F12`
Editor Switch to previous editor	`Ctrl` + `Page Down`
Editor Switch to next editor	`Ctrl` + `Page Up`
Editor Maximize or restore current editor window (also works with other windows)	`Ctrl` + `M`
Editor Show the list of open editors	`Ctrl` + `E`
Editor Show the list of open editors, but switch immediately when you release <keybs>Ctrl</keybs>	`Ctrl` + `F6`
Editor Go to previous / next editor windows	`Alt` + `← →`
Editor Open Editor Window Option menu	`Alt` + `-`
Editor Show view menu	`Ctrl` + `F10`
Editor n Show / hide line numbers	`Ctrl` + `F10` then `N`
Editor Show or hide the diff. column on the left (column that indicates changes since last save)	`Ctrl` + `↑ Shift` + `Q`
Editor Zoom in	`Ctrl` + `↑ Shift` + `+`
Editor Zoom out	`Ctrl` + `↑ Shift` + `-`
Navigation in editor window Jump to beginning of indention. Press twice to jump to beginning of the line	`Home`
Navigation in editor window Jump to end of line	`End`
Navigation in editor window Jump to beginning of source	`Ctrl` + `Home`
Navigation in editor window Jump to end of source	`Ctrl` + `End`
Navigation in editor window Jump one word to the left / right	`Ctrl` + `← →`
Navigation in editor window Jump to previous / next method	`Ctrl` + `↑ Shift` + `↑ ↓`
Navigation in editor window Jump to line number	`Ctrl` + `L`
Navigation in editor window Jump to last edited location	`Ctrl` + `Q`
Navigation in editor window Jump to previous / next compiler syntax warning or error	`Ctrl` + `.`
Navigation in editor window Jump to previous / next compiler syntax warning or error	`Ctrl` + `,`
Navigation in editor window With a bracket selected: Jump to matching closing or opening bracket	`Ctrl` + `↑ Shift` + `P`
Navigation in editor window Collapse / expand current method or class	`Ctrl` + `[`
Navigation in editor window Collapse / expand current method or class	`Ctrl` + `]`
Navigation in editor window Collapse / expand current method or class	`Ctrl` + `Num -`
Navigation in editor window Collapse / expand all methods or classes	`Ctrl` + `Num *`
Navigation in editor window Scroll editor without changing cursor position	`Ctrl` + `↑ ↓`
Navigation in editor window Previous sub-tab	`Alt` + `Page Up`
Navigation in editor window Next sub-tab	`Alt` + `Page Down`
Selecting text Expand selection by one character to the left or right	`↑ Shift` + `← →`
Selecting text Expand selection to the next or previous word	`Ctrl` + `↑ Shift` + `← →`
Selecting text Expand selection by one line up or down	`↑ Shift` + `↑ ↓`
Selecting text Expand selection to end of line	`↑ Shift` + `End`
Selecting text Expand eslection to beginning of line	`↑ Shift` + `Home`
Selecting text Expand selection to current element	`Alt` + `↑ Shift` + `↑`
Selecting text Expand selection to previous or next element	`Alt` + `↑ Shift` + `← →`
Selecting text Reduce previously expanded selection by one step	`Alt` + `↑ Shift` + `↓`
Editing text Copy	`Ctrl` + `C`
Editing text Cut	`Ctrl` + `X`
Editing text Paste	`Ctrl` + `V`
Editing text Undo last action	`Ctrl` + `Z`
Editing text Redo last undone action	`Ctrl` + `Y`
Editing text Delete line	`Ctrl` + `D`
Editing text Move current line or selection up or down	`Alt` + `↑ ↓`
Editing text Duplicate current line or selection up or down	`Ctrl` + `Alt` + `↑ ↓`
Editing text Delete next word	`Ctrl` + `Del`
Editing text Delete previous word	`Ctrl` + `⬅ Backspace`
Editing text Enter line below current line	`↑ Shift` + `⤶ Enter`
Editing text Enter line above current line	`↑ Shift` + `Ctrl` + `⤶ Enter`
Editing text Switch between insert and overwrite mode	`Insert`
Editing text Convert selection to lowercase	`↑ Shift` + `Ctrl` + `Y`
Editing text Convert selection to uppercase	`↑ Shift` + `Ctrl` + `X`
Search and replace Open find and replace dialog box	`Ctrl` + `F`
Search and replace Find previous occurence of the search term	`Ctrl` + `K`
Search and replace Find next occurence of the search term	`Ctrl` + `↑ Shift` + `K`
Search and replace Search Workspace (Java search, Task search, and File search)	`Ctrl` + `H`
Search and replace Incremental search forward	`Ctrl` + `J`
Search and replace Incremental search backwards	`Ctrl` + `↑ Shift` + `J`
Search and replace Open a resource search dialog to find any class	`Ctrl` + `↑ Shift` + `O`
Indentions and comments Increase indent of selected text	`⭾ Tab`
Indentions and comments Decrease indent of selected text	`↑ Shift` + `⭾ Tab`
Indentions and comments Correct indention of selected text or current line	`Ctrl` + `I`
Indentions and comments Auto format all code in editor using code formatter	`Ctrl` + `↑ Shift` + `F`
Indentions and comments Comment / uncomment line or selection (add //)	`Ctrl` + `/`
Indentions and comments Toggle comments	`Ctrl` + `↑ Shift` + `C`
Indentions and comments *Add block comment arount selection (add /.../)**	`Ctrl` + `↑ Shift` + `/`
Indentions and comments Remove block comment	`Ctrl` + `↑ Shift` + `\`
Indentions and comments Add element comment (add / ... /)*	`Alt` + `↑ Shift` + `J`
Editing source code Open content assist (e.g. show available methods or field names)	`Ctrl` + `Space`
Editing source code Open quick fix and quick assist	`Ctrl` + `1`
Editing source code Suggest word completion (after typing at least one letter). Press repeatedly until reaching correct name	`Alt` + `/`
Editing source code Deactivate or activate Smart Insert Mode (automatic indention, automatic brackets, etc.)	`Ctrl` + `↑ Shift` + `Insert`
Code information Show code outline or structure	`Ctrl` + `O`
Code information Open class, method, or variable information (show as tooltip text)	`F2`
Code information Open declaration: Jump to Declaration of selected class, method, or parameter	`F3`
Code information Open Type Hierarchy window for selected item	`F4`
Code information Show or open Quick Type Hierarchy for selected item	`Ctrl` + `T`
Code information Open type in hierarchy	`Ctrl` + `↑ Shift` + `T`
Code information Open call hierarchy	`Ctrl` + `Alt` + `H`
Code information Find occurrences of expression in current file	`Ctrl` + `↑ Shift` + `U`
Code information Open declaration or implementation	`Ctrl` + `Mouse movement`
Refactoring Rename selected element and all references	`Alt` + `↑ Shift` + `R`
Refactoring Move selected element to other class or file (with complete method or class selected)	`Alt` + `↑ Shift` + `V`
Refactoring Change method signature (with method name selected)	`Alt` + `↑ Shift` + `C`
Refactoring Extract selection to method	`Alt` + `↑ Shift` + `M`
Refactoring Extract local variable: Create and assign a variable from selected expression	`Alt` + `↑ Shift` + `L`
Refactoring Inline selected local variables, methods or constants when possible (replaces variable with its declarations/ assignment and puts it directly into the statements)	`Alt` + `↑ Shift` + `I`
Running and debugging Save and launch application	`Ctrl` + `F11`
Running and debugging Debug	`F11`
Running and debugging Next step (line by line)	`F6`
Running and debugging Step out	`F7`
Running and debugging Skip to next breakpoint	`F8`
Other Switch forward between panels. Useful for switching back and forth between Package Explorer and Editor	`Ctrl` + `F7`
Other Switch backward between panels. Useful for switching back and forth between Package Explorer and Editor	`Ctrl` + `↑ Shift` + `F7`
Other Print	`Ctrl` + `P`
Other Open Eclipse help	`F1`
Other Show context menu	`↑ Shift` + `F10`
Team (SVN Subversive) Synchronize with repository	`Ctrl` + `Alt` + `S`
Team (SVN Subversive) Commit	`Ctrl` + `Alt` + `C`
Team (SVN Subversive) Update	`Ctrl` + `Alt` + `U`
Team (SVN Subversive) Update to revision	`Ctrl` + `Alt` + `D`
Team (SVN Subversive) Merge	`Ctrl` + `Alt` + `E`
Team (SVN Subversive) Show properties	`Ctrl` + `Alt` + `T`
Team (SVN Subversive) Add to svn:ignore	`Ctrl` + `Alt` + `I`