Comment comparison
There is a wide variety of syntax styles for declaring comments in source code. BlockComment in italics is used here to indicate block comment style. InlineComment in italics is used here to indicate inline comment style.
| Language | In-line comment | Block comment |
|---|---|---|
| Ada, Eiffel, Euphoria, Occam, SPARK, ANSI SQL, ToolBook OpenScript, and VHDL | -- InlineComment |
|
| ALGOL 60 | comment BlockComment; |
|
| ALGOL 68 | ¢ BlockComment ¢
|
|
| AppleScript | -- InlineComment |
(* BlockComment *) |
| Assembly language (varies) | ; InlineComment one example (most assembly languages use line comments only) |
|
| AutoHotkey | ; InlineComment |
/* BlockComment */ |
| AWK, Bash, Bourne shell, C shell, Maple, Python, R, Tcl, and Windows PowerShell | # InlineComment |
<# BlockComment #> |
| BASIC (various dialects): | 'InlineComment (not all dialects)
|
|
| C (K&R, ANSI/C89/C90), CHILL, PL/I, and REXX | /* BlockComment */ |
|
| C (C99), C++, Go, and JavaScript | // InlineComment |
/* BlockComment */ |
| C# | // InlineComment/// InlineComment (XML documentation comment) |
/* BlockComment *//** BlockComment */ (XML documentation comment) |
| Cobol | InlineComment (when * is in column 7) |
|
| Curl | || InlineComment |
|# BlockComment #|
|
| Cobra | # InlineComment |
/# BlockComment #/ (nestable) |
| D | // InlineComment/// Documentation InlineComment (ddoc comments) |
/* BlockComment *//** Documentation BlockComment */ (ddoc comments)
|
| DCL | $! InlineComment |
|
| ECMAScript (JavaScript, ActionScript, etc.) | // InlineComment |
/* BlockComment */ |
| Forth | InlineComment |
( BlockComment ) (single line only)
|
| FORTRAN 66/77 | C InlineComment (the letter 'C' in the first column makes the entire line a comment). |
|
| Fortran 90 | ! InlineComment (all characters on the line, from the exclamation mark onwards, are comments) |
|
| Haskell | -- InlineComment |
{- BlockComment -} |
| Java | // InlineComment |
/* BlockComment */
|
| Lisp and Scheme | ; InlineComment |
#| BlockComment |# |
| Lua | -- InlineComment |
--[==[ BlockComment]==] (variable number of = signs) |
| Maple | # InlineComment |
(* BlockComment *) |
| Mathematica | % (* BlockComment *) |
|
| Matlab | % InlineComment |
%{Note: Both percent–bracket symbols must be the only non-whitespace characters on their respective lines. |
| Object Pascal (Delphi) | // InlineComment |
(* BlockComment *){ BlockComment } |
| OCaml | (* BlockComment (* nestable *) *) |
|
| Pascal, Modula-2, Modula-3, Oberon, and ML: | (* BlockComment *) (OCaml comments are nestable) |
|
| Perl and Ruby | # InlineComment |
=begin (POD documentation comment)
|
| PHP | # InlineComment// InlineComment |
/* BlockComment *//** Documentation BlockComment */ (PHP Doc comments) |
| PILOT | R:InlineComment |
|
| PL/SQL and TSQL | -- InlineComment |
/* BlockComment */ |
| REALbasic | ' InlineComment// InlineCommentrem InlineComment |
|
| SAS | * BlockComment;/* BlockComment */ |
|
| Seed7 | # InlineComment |
(* BlockComment *) |
| Simula | comment BlockComment;! BlockComment; |
|
| Smalltalk | "BlockComment" |
|
| Smarty | {* BlockComment *} |
|
| Standard ML | (* BlockComment *) |
|
| TeX, LaTeX, PostScript, Erlang, and S-Lang | % InlineComment |
|
| Texinfo | @c InlineComment
|
|
| TUTOR | * InlineCommentcommand $$ InlineComment |
|
| Visual Basic | ' InlineCommentRem InlineComment |
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| Visual Basic .NET | ' InlineComment
|
|
| Visual Prolog | % InlineComment |
/* BlockComment */ |
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