# Comments

Comments are lines in a source file that have been marked to be ignored by the compiler. Two styles of comments are supported by current C/C++ compilers:

- `/* C style comment (block comment) */`
- `// C++ style comment (line comment)`

## Line Comment

You can quickly comment out one or more lines of code by inserting the leading characters `//` at the beginning of the line. To do so, select the line (or lines) of code you want to comment out and press CTRL+/ (slash).

## Line Uncomment

To uncomment select the line (or lines) of code, and press CTRL+/ (slash) again.

Tip: The characters `/* */` on lines that are already commented out, are not affected when you comment and uncomment code using line comment.

## Block Comment

You can comment out selected block of code with C style comment `/* */`. To do so, select the block of code you want to comment out and press CTRL+Shift+/ (slash).

## Block Uncomment

To uncomment select the code inside commented out block, and press CTRL+SHIFT+\ (backslash).

## Multiline comment template

You can use the Content Assist feature to insert a multi-line comment before a function. In the C++ editor, type com then press Ctrl+Space. Select default multiline comment template and press Enter. The following code is entered at the cursor location:

    /*
     * author userid
     *
     * To change this generated comment edit the template variable "comment":
     * Window > Preferences > C/C++ > Editor > Templates.
     */

To change the default comment click Window > Preferences > C/C++ > Code Style > Code Templates. For more information see the Content Assist section.

Content Assist and code completion

Customizing the C++ editor
Commenting out code

C/C++ editor preferences