Comparison of programming languages (syntax)

Expressions

• Lisp )

• Fortran *

• Forth 2 3 + 4 5 ** *

• TUTOR $$ note implicit multiply operator

  Statements

• statement separators;
• statement terminators; and
• line continuation

Line continuation

• Ada – Lines terminate with semicolon
• C# – Lines terminate with semicolon
• JavaScript – Lines terminate with semicolon
• Lua
• OCaml

• Fortran 90, Fortran 95, Fortran 2003, Fortran 2008

• bash and other Unix shells
• C and C++ preprocessor
• Mathematica and Wolfram Language
• Python
• Ruby
• JavaScript – only within single- or double-quoted strings

• PowerShell

• SQL*Plus

• AutoIt
• Cobra
• Visual Basic
• Xojo

• MATLAB: The ellipsis token need not be the last characters on the line, but any following it will be ignored.

• Ruby

• Batch file: starting a parenthetical block can allow line continuation
• Ruby: left parenthesis, left square bracket, or left curly bracket

• Ruby

• AutoHotkey: Any expression operators except ++ and --, as well as a comma or a period

• Vimscript

• Turbo Assembler: \
• m4: dnl
• TeX: %

• Fortran 77: A non-comment line is a continuation of the previous non-comment line if any non-space character appears in column 6. Comment lines cannot be continued.
• COBOL: String constants may be continued by not ending the original string in a PICTURE clause with ', then inserting a - in column 7
• TUTOR: Lines starting with a tab continue the previous command.

• C and C++ preprocessor: The string is ended normally and continues by starting with a quote on the next line.

  Libraries

• ASP: #include file="filename"
• AutoHotkey, AutoIt, C, C++: #include "filename", #include <filename>
• COBOL: COPY filename.
• Falcon: load "filename"
• Fortran: include 'filename'
• Lua: require
• Mathematica and Wolfram Language: Import
• MATLAB: addpath
• Objective-C: #import "filename", #import <filename>
• Perl: require "filename";
• PHP: include "filename";, require "filename";
• Prolog: :-include.
• Pick Basic: include program, #include program
• R: source
• Red: load %filename
• Rust: include!;

• Ada: with package
• C, C++: #include filename
• Cobra: use Package.Name
• D: import package.module;, import altname = package.module;
• Falcon: load module, load module.submodule
• Fortran 90+: use module, use module, only : identifier
• Go: import altname "package/name"
• Haskell: import Module, import qualified Module as M
• Java, MATLAB, kotlin: import package.*
• JavaScript: import altname from "modname";, import "modname";
• Lua: require
• Mathematica and Wolfram Language: <<name
• Oberon: IMPORT module
• Objective-C: @import module;
• Pascal: uses unit
• Perl: use Module;, use Module qw;
• Prolog: :-use_module.
• Python: import module, from module import *
• Rust: mod modname;, # mod altname;, extern crate libname;, extern crate libname as altname;
• R: library
• Scala: import package._, import package
• Swift: import module

• Falcon: import class
• Java, MATLAB, kotlin: import package.class
• JavaScript: import class from "modname";, import from "modname";, import from "modname";
• PHP: use Namespace\ClassName;, use Namespace\ClassName as AliasName;
• Python: from module import class
• Scala: import package.class, import package., import package._

• D: import package.module : symbol;, import package.module : altsymbolname = symbol;
• Haskell: import Module
• JavaScript: import function from "modname";, import from "modname";, import from "modname";
• MATLAB: import package.function
• Perl: use Module ;
• PHP: use function Namespace\function_name;, use Namespace\function_name as function_alias_name;
• Python: from module import function
• Rust: use module::submodule::symbol;, use module::submodule::;, use module::submodule::symbol as altname;
• Scala: import package.class.function, import package.class.

• PHP: use const Namespace\CONST_NAME;

• Java: import package.*, import package.class
• OCaml: open module

• Go: import altname "package/name"
• JavaScript: import altname from "modname";
• Python: import module

  Blocks

• Curly bracket programming languages: C, C++, Objective-C, Go, Java, JavaScript/ECMAScript, C#, D, Perl, PHP, Rust, Scala, S-Lang, Swift, Windows PowerShell, Haskell, AutoHotkey

• OCaml, Prolog, Standard ML

• Smalltalk

• Ada, ALGOL, Pascal, Ruby, OCaml, SCL, Simula, Erlang.

• PL/I, REXX

• Bash, Visual Basic, Fortran, TUTOR, Visual Prolog

• Lua, Ruby, Seed7

• Ruby, OCaml, MATLAB, Lua

• Scheme

• Lisp

• Clojure

• Off-side rule languages: Cobra, CoffeeScript, F#, Haskell, occam, Python
• Free-form languages: most descendants from ALGOL ; Lisp languages

• Ada, Visual Basic, Seed7: if... end if
• APL: :If... :EndIf or :If... :End
• Bash, sh, and ksh: if... fi, do... done, case... esac;
• ALGOL 68: begin... end, , if... fi, do... od
• Lua, Pascal, Modula-2, Seed7: repeat... until
• COBOL: IF... END-IF, PERFORM... END-PERFORM, etc. for statements;... . for sentences.
• Visual Basic.Net: If... End If, For... Next, Do... Loop
• Small Basic: If... EndIf, For... EndFor, While... EndWhile

  Comments

• style
• parse rules
• recursivity
• uses

  Inline comments

Block comments

Unique variants

• Indenting lines in Fortran 66/77 is significant. The actual statement is in columns 7 through 72 of a line. Any non-space character in column 6 indicates that this line is a continuation of the previous line. A 'C' in column 1 indicates that this entire line is a comment. Columns 1 though 5 may contain a number which serves as a label. Columns 73 though 80 are ignored and may be used for comments; in the days of punched cards, these columns often contained a sequence number so that the deck of cards could be sorted into the correct order if someone accidentally dropped the cards. Fortran 90 removed the need for the indentation rule and added inline comments, using the ! character as the comment delimiter.

• In fixed format code, line indentation is significant. Columns 1–6 and columns from 73 onwards are ignored. If a * or / is in column 7, then that line is a comment. Until COBOL 2002, if a D or d was in column 7, it would define a "debugging line" which would be ignored unless the compiler was instructed to compile it.

• Cobra supports block comments with "/#... #/" which is like the "/*... */" often found in C-based languages, but with two differences. The # character is reused from the single-line comment form "#...", and the block comments can be nested which is convenient for commenting out large blocks of code.

• Curl supports block comments with user-defined tags as in |foo#... #foo|.

• Like raw strings, there can be any number of equals signs between the square brackets, provided both the opening and closing tags have a matching number of equals signs; this allows nesting as long as nested block comments/raw strings use a different number of equals signs than their enclosing comment: --comment --=] . Lua discards the first newline that directly follows the opening tag.

• Block comments in Perl are considered part of the documentation, and are given the name Plain Old Documentation. Technically, Perl does not have a convention for including block comments in source code, but POD is routinely used as a workaround.

• PHP supports standard C/C++ style comments, but supports Perl style as well.

• The use of the triple-quotes to comment-out lines of source, does not actually form a comment. The enclosed text becomes a string literal, which Python usually ignores.

• Raku uses #` to denote block comments. Raku actually allows the use of any "right" and "left" paired brackets after #`. Brackets are also allowed to be nested inside comments.

• Block comment in Ruby opens at =begin line and closes at =end line.

• The region of lines enclosed by the #<tag> and #</tag> delimiters are ignored by the interpreter. The tag name can be any sequence of alphanumeric characters that may be used to indicate how the enclosed block is to be deciphered. For example, #<latex> could indicate the start of a block of LaTeX formatted documentation.

• The next complete syntactic component can be commented out with #;.

• Many esoteric programming languages follow the convention that any text not executed by the instruction pointer or otherwise assigned a meaning, is considered a "comment".

  Comment comparison