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{{task|Basic language learning}}
[[Category:Initialization]]
[[Category:Simple]]
;Task:
Create the simplest possible program that is still considered "correct."
<br><br>
=={{header|11l}}==
An empty text file is a correct 11l program that does nothing.
=={{header|360 Assembly}}==
Return to caller
<syntaxhighlight lang="360 assembly"> BR 14
END</syntaxhighlight>
=={{header|4ME}}==
===4ME v1===
An empty .wm file was considerd as a valid 4ME program.
===4ME v1.1===
There are two ways to make an empty program in 4ME
P:
E:
or
P:
and if you try to remove the <code>P:</code> command. The interpriter will emit:
S1245
P: IS MISSING
=={{header|6502 Assembly}}==
===Commodore 64===
<syntaxhighlight lang="6502asm">org $0801 ;start assembling at this address
db $0E,$08,$0A,$00,$9E,$20,$28,$32,$30,$36,$34,$29,$00,$00,$00 ;required init code
rts ;return to basic</syntaxhighlight>
===Nintendo Entertainment System===
Without an infinite loop the program counter will execute undefined behavior, depending on how "empty" bytes are padded. If we're generous and assume that empty bytes are padded with <code>NOP</code>, eventually the program counter will attempt to execute the interrupt vectors as executable code. If we assume that an "empty program" needs to not crash (even though you really can't tell the difference with nothing on screen), we need a way to "trap" the program counter.
<syntaxhighlight lang="6502asm">.org $8000 ;usually $8000 but it depends on the mapper.
RESET: ;execution starts here
JMP RESET
NMI: ;NMI can't happen if the screen is off. No need for RTI
IRQ: ;this will never occur without a CLI command.
.org $FFFA
;all 6502 based hardware uses this section of memory to hold the addresses of interrupt routines
;as well as the entry point.
dw NMI ;FFFA-FFFB
dw RESET ;FFFC-FFFD ;this has to be defined or else the program counter will jump to an unknown location
dw IRQ ;FFFE-FFFF</syntaxhighlight>
=={{header|68000 Assembly}}==
This mostly depends on the implementation, but <code>JMP *</code> will typically suffice for embedded hardware.
==
After you get to the main program, you'll need to kick the watchdog every frame to prevent the BIOS from resetting the machine. This is done by writing any byte to memory address 0x00300001. Other than that, an endless loop will suffice (assuming you have a proper cartridge header and a vBlank routine that does nothing except check for bios vblank and return.)
<syntaxhighlight lang="68000devpac">forever:
MOVE.B D0,$300001
JMP forever</syntaxhighlight>
=={{header|8051 Assembly}}==
Continuously loops.
<syntaxhighlight lang="asm">ORG RESET
jmp $</syntaxhighlight>
=={{header|8086 Assembly}}==
===Boot Sector Program===
<syntaxhighlight lang="asm">main segment
start:
jmp start ;2 bytes
padding byte 508 dup (90h)
bootcode byte 55h,0AAh
main ends</syntaxhighlight>
If your assembler assembles the code above as an EXE file, you'll need to use a hex editor to strip the EXE header so that it fits exactly into 512 bytes.
===16-Bit x86 for EXE Files===
<syntaxhighlight lang="asm">.model small ;.exe file
.stack 1024 ;this value doesn't matter, I chose this arbitrarily
.data
;not needed in an empty program
.code
mov ax,4C00h
int 21h ;exit this program and return to MS-DOS</syntaxhighlight>
===32-Bit x86===
<syntaxhighlight lang="asm">end</syntaxhighlight>
However, if the program needs to exit with an exit code of zero:
<syntaxhighlight lang="asm"> segment .text
global _start
_start:
mov eax, 60
xor edi, edi
syscall
end</syntaxhighlight>
=={{header|AArch64 Assembly}}==
Simulates system call exit(0). In AArch64, the system call number is passed via x8, and the syscall number for exit is 93.
<syntaxhighlight lang="arm_assembly">.text
.global _start
_start:
mov x0, #0
mov x8, #93
svc #0</syntaxhighlight>
=={{header|ABAP}}==
Note that the statement "start-of-selection." is implicitly added. This event block needs to be present in executable programs, it's comparable to the main function in other programming languages.
<syntaxhighlight lang="abap">
report z_empty_program.
</syntaxhighlight>
=={{header|Action!}}==
<syntaxhighlight lang="action!"></syntaxhighlight>
{{out}}
[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Empty_program.png Screenshot from Atari 8-bit computer]
=={{header|Ada}}==
{{works with|GCC|4.1.2}}
<syntaxhighlight lang="ada">procedure Empty is
begin
null;
end;</syntaxhighlight>
=={{header|Agena}}==
Actually nothing is valid code, too.
<syntaxhighlight lang="agena"></syntaxhighlight>
=={{header|Aime}}==
The nil input is a valid program.
<syntaxhighlight lang="aime"></syntaxhighlight>
=={{header|ALGOL 60}}==
<syntaxhighlight lang="algol60">'BEGIN' 'END'</syntaxhighlight>
=={{header|ALGOL 68}}==
=== Brief form ===
<syntaxhighlight lang="algol68">~</syntaxhighlight>
=== BOLD form ===
<syntaxhighlight lang="algol68">SKIP</syntaxhighlight>
=={{header|ALGOL W}}==
In Algol W, a blank statement is a valid statement and a program is a statement followed by a dot. Hence "." is the smallest valid program.
<syntaxhighlight lang="algolw">.</syntaxhighlight>
=={{header|AmigaE}}==
<syntaxhighlight lang="amigae">PROC main()
ENDPROC</syntaxhighlight>
=={{header|AppleScript}}==
An empty .scpt file is considered the smallest runnable code, but the following would also be acceptable.
<syntaxhighlight lang="applescript">return</syntaxhighlight>
=={{header|Argile}}==
The empty string or file are valid and do nothing.
<syntaxhighlight lang="argile"></syntaxhighlight>
=={{header|ARM Assembly}}==
===GNU/Linux RaspberryPi===
<syntaxhighlight lang="arm_assembly">.text
.global _start
_start:
mov r0, #0
mov r7, #1
svc #0 </syntaxhighlight>
===Game Boy Advance===
The Nintendo logo is loaded from the cartridge, and the Game Boy Advance's firmware won't boot the game without it. So an empty program can't be run at all. Thus a minimum of a valid cartridge header is required for an empty program that the Game Boy Advance can actually run.
The first four bytes of the cartridge header are an unconditional branch instruction to the program's start. Simply duplicate this instruction at that address and voila:
<syntaxhighlight lang="arm_assembly">ProgramStart:
b ProgramStart ;don't do this on a real game boy, you'll drain the batteries faster than usual.</syntaxhighlight>
Hardware interrupts will not occur if you never enable them, so there is no need to store the interrupt service procedure's address in address $03FFFFFC to prevent a crash. The Game Boy Advance has no "exit" <code>SWI</code> call (the closest is the undocumented hard reset) so this is as close as you can get.
=={{header|ArnoldC}}==
<syntaxhighlight lang="arnoldc">IT'S SHOWTIME
YOU HAVE BEEN TERMINATED</syntaxhighlight>
=={{header|Arturo}}==
A completely empty script is a valid Arturo program.
<syntaxhighlight lang="rebol"></syntaxhighlight>
=={{header|Asymptote}}==
<syntaxhighlight lang="asymptote"></syntaxhighlight>
=={{header|AutoHotkey}}==
An empty script would be enough. Adding "#Persistent" makes it persistent.
<syntaxhighlight lang="autohotkey">#Persistent</syntaxhighlight>
=={{header|AutoIt}}==
A single comment can be considered a valid program that does nothing.
<syntaxhighlight lang="autoit">;nothing</syntaxhighlight>
=={{header|Avail}}==
Avail files require a header block (that is generally omitted from the examples here). The shortest valid header would only include the module name, which can be reduced to 1 character, assuming the filename is set to match. For "a.avail", this gives the empty program:
<syntaxhighlight lang="avail">Module "a"
Body</syntaxhighlight>
This can be further shortened by removing unambiguous whitespace to:
<syntaxhighlight lang="avail">Module"a"Body</syntaxhighlight>
For all practical purposes, this header is useless in any other program. It does not import the standard library "Avail" (or any alternatives), so it has access to no methods, types, or values. Here's a short program capable of output:
<syntaxhighlight lang="avail">Module"a"Uses"Avail"Body Print:"!";</syntaxhighlight>
Or with more traditional spacing:
<syntaxhighlight lang="avail">Module "a"
Uses "Avail"
Body
Print:"!";</syntaxhighlight>
Note however that this output is only available as a ''compile-time'' side effect. A program defining a run-time entry point would include an <code>Entries</code> header section, or export its content for an entry point in another module to run.
=={{header|AWK}}==
The empty string (or file) is recognised as valid program that does nothing.
The program
<syntaxhighlight lang="awk"> 1</syntaxhighlight>
is the simplest useful program, equivalent to
<syntaxhighlight lang="awk">// {print}</syntaxhighlight>
I.e. match every input-line, and print it. <br>
Like the UNIX command 'cat', it prints every line of the files given as arguments,
or (if no arguments are given) the standard input.
=={{header|Axe}}==
Most Axe examples omit the executable name, but it is shown in this example for completeness.
<syntaxhighlight lang="axe">:.PRGMNAME
:</syntaxhighlight>
=={{header|BASIC}}==
{{works with|QBASIC}}
{{works with|Quick BASIC}}
{{works with|FreeBASIC}}
{{works with|uBasic/4tH}}
An empty file is a correct program. It won't be near empty as an executable file, though.
<syntaxhighlight lang="qbasic"></syntaxhighlight>
{{works with|ZX Spectrum Basic}}
On the ZX Spectrum, we can have a completely empty program with no lines. Here we attempt to run the empty program:
<syntaxhighlight lang="basic">RUN</syntaxhighlight>
0 OK, 0:1
==={{header|Applesoft BASIC}}===
<syntaxhighlight lang="applesoftbasic"></syntaxhighlight>
=={{header|Batch File}}==
On Windows XP and older, an empty batch file is syntactically correct and does nothing.
<syntaxhighlight lang="dos"></syntaxhighlight>
But on Windows 7, an empty .bat file is not recognized and thus a character must exist in it. Some valid characters are <code>: @ %</code>
<syntaxhighlight lang="dos">:</syntaxhighlight>
=={{header|BaCon}}==
In BaCon an empty program is a valid program.
<syntaxhighlight lang="bacon"></syntaxhighlight>
=={{header|BASIC256}}==
<syntaxhighlight lang="freebasic"></syntaxhighlight>
=={{header|BBC BASIC}}==
In BBC BASIC an empty program is syntactically correct.
<syntaxhighlight lang="bbcbasic"></syntaxhighlight>
=={{header|bc}}==
An empty file is a valid program.
=={{header|Binary Lambda Calculus}}==
At 4 bits, or half a byte, the smallest BLC program is `cat' :
<pre>00 10</pre>
corresponding to the smallest valid lambda term, the identity function \x.x
=={{header|Beef}}==
<syntaxhighlight lang="csharp">using System;
class Program
{
public static void Main()
{
}
}
</syntaxhighlight>
=={{header|Beeswax}}==
<syntaxhighlight lang="beeswax">*</syntaxhighlight>
(create 6 bees moving in all 6 cardinal directions)
or
<syntaxhighlight lang="beeswax">\</syntaxhighlight>
(create 2 bees moving in “northwest” and “southeast” directions)
or
<syntaxhighlight lang="beeswax">_</syntaxhighlight>
(create 2 bees moving left and right)
or
<syntaxhighlight lang="beeswax">/</syntaxhighlight>
(create 2 bees moving in “northeast” and “southwest” directions)
A valid beeswax program needs at least one of these bee spawning symbols, as a program without bees is not executable. All bees that step off the honeycomb (program area) are automatically deleted, and the program ends if no bees are left.
=={{header|Befunge}}==
@
The halt command '''@''' is required because code wraps around. An empty file would be an infinite loop.
=={{header|bootBASIC}}==
<syntaxhighlight lang="bootbasic"></syntaxhighlight>
=={{header|BQN}}==
An empty program in BQN produces an error. There must be at least one line which returns a value.
Any valid literal works to make a program run. The shortest way is to use a single digit, or a predefined constant, like <code>π</code> or <code>∞</code>.
<syntaxhighlight lang="bqn">∞</syntaxhighlight>
[https://mlochbaum.github.io/BQN/try.html#code=4oie Try It!]
=={{header|Bracmat}}==
An empty file is a valid program. However you need to load it, which requires a statement. In a Linux terminal, you could do
<syntaxhighlight lang="bracmat">touch empty
bracmat 'get$empty'</syntaxhighlight>
In DOS, you can do
<syntaxhighlight lang="dos">touch empty
bracmat get$empty</syntaxhighlight>
If we drop the requirement that the shortest program is stored in a file, we can do
<syntaxhighlight lang="bash">bracmat ''</syntaxhighlight>
(Linux)
or
<syntaxhighlight lang="dos">bracmat ""</syntaxhighlight>
(Windows)
If two quotes to demarcate an empty string are counted as bigger than a single undemarcated non-empty expression, we can do
bracmat .
The dot is a binary operator. So the input consists of three nodes: the operator and its lhs and rhs, both empty strings in this case. If three nodes is too much, consider a slightly bigger glyph, such as the hyphen, which is a prefix, not a binary operator:
bracmat -
You also can start Bracmat without arguments, in which case it will run in interactive mode. Now press the Enter key. You have just run the shortest valid Bracmat program.
=={{header|Brainf***}}==
<pre>Empty program</pre>
''Note:'' this works as all non-instruction characters are considered comments. Alternatively, a zero-byte file also works.
=={{header|Brlcad}}==
Pressing enter from the mged prompt, just returns another prompt, so I suppose that is the smallest possible program. However, before we can draw anything we at least need to open a database:
<syntaxhighlight lang="mged">opendb empty.g y</syntaxhighlight>
=={{header|Bruijn}}==
The smallest program in bruijn is the identity function (\x.x) and returns its input:
<syntaxhighlight>main [0]</syntaxhighlight>
=={{header|C}}==
{{works with|C89}}
<syntaxhighlight lang="c">main()
{
return 0;
}</syntaxhighlight>
As of C99 the return type is required, but the return statement is not.
{{works with|C99}}
<syntaxhighlight lang="c">int main() { }</syntaxhighlight>
This is technically undefined behavior but on 8086 compatible processors <code>195</code> corresponds to the <code>ret</code> assembly instruction.
{{works with|C on 8086 compatible processors}}
<syntaxhighlight lang="c">const main = 195;</syntaxhighlight>
=={{header|C sharp|C#}}==
As of C# 9.0, an empty text file is a correct C# program that does nothing.
=={{header|C++}}==
{{works with|g++|4.8.1}}
<syntaxhighlight lang="cpp">int main(){}</syntaxhighlight>
=={{header|Clean}}==
<syntaxhighlight lang="clean">module Empty
Start world = world</syntaxhighlight>
Compile the project with ''No Console'' or ''No Return Type'' to suppress printing of the value of the world.
==={{header|Chipmunk Basic}}===
An empty text file is a correct Chipmunk Basic program that does nothing.
=={{header|Clojure}}==
An empty file is the simplest valid Clojure program.
=={{header|CLU}}==
This is the shortest program that actually produces a working executable (that does nothing).
<syntaxhighlight lang="text">start_up = proc ()
end start_up</syntaxhighlight>
[[Portable CLU]] will compile the empty file without complaint, but not produce an
object file.
=={{header|COBOL}}==
{{works with|OpenCOBOL|2.0}}
<syntaxhighlight lang="cobol"></syntaxhighlight>
=={{header|CoffeeScript}}==
<syntaxhighlight lang="coffeescript"></syntaxhighlight>
=={{header|Common Lisp}}==
<syntaxhighlight lang="lisp">()</syntaxhighlight>
<syntaxhighlight lang="lisp">.</syntaxhighlight>
=={{header|Component Pascal}}==
BlackBox Component Builder;
<syntaxhighlight lang="oberon2">
MODULE Main;
END Main.
</syntaxhighlight>
=={{header|Computer/zero Assembly}}==
The smallest legal program is a single Stop instruction.
<syntaxhighlight lang="czasm"> STP</syntaxhighlight>
=={{header|Crystal}}==
<syntaxhighlight lang="crystal"></syntaxhighlight>
=={{header|D}}==
<syntaxhighlight lang="d">void main() {}</syntaxhighlight>
=={{header|Dart}}==
<syntaxhighlight lang="dart">main() {}</syntaxhighlight>
=={{header|dc}}==
An empty file is a valid program.
=={{header|DCL}}==
An empty file is a valid program.
=={{header|Delphi}}==
:''See [[#Pascal|Pascal]]''
=={{header|Dyalect}}==
Dyalect is not very happy with a completely empty source code file, however a pair of curly brackets would do:
<syntaxhighlight lang="dyalect">{}</syntaxhighlight>
This program would evaluate and return "nil".
=={{header|Déjà Vu}}==
<syntaxhighlight lang="dejavu"></syntaxhighlight>
Shortest module that works with <code>!import</code>:
<syntaxhighlight lang="dejavu">{}</syntaxhighlight>
=={{header|E}}==
The shortest possible program:
<pre></pre>
This is equivalent to:
<syntaxhighlight lang="e">null</syntaxhighlight>
=={{header|EasyLang}}==
<syntaxhighlight lang=text>
#
</syntaxhighlight>
=={{header|eC}}==
<pre></pre>
or
<syntaxhighlight lang="ec">class EmptyApp : Application
{
void Main()
{
}
}</syntaxhighlight>
=={{header|EchoLisp}}==
<syntaxhighlight lang="scheme">
</syntaxhighlight>
=={{header|Ecstasy}}==
<syntaxhighlight lang="java">
module EmptyProgram {
void run() {
}
}
</syntaxhighlight>
=={{header|ed}}==
<pre></pre>
=={{header|EDSAC order code}}==
The smallest program that will load and run without error. Apart from <tt>ZF</tt>, the 'stop' order, it consists solely of directives to the loader.
<syntaxhighlight lang="edsac">T64K [ set load point ]
GK [ set base address ]
ZF [ stop ]
EZPF [ begin at load point ]</syntaxhighlight>
=={{header|Egel}}==
The smallest program contains nothing.
<syntaxhighlight lang="egel">
</syntaxhighlight>
=={{header|EGL}}==
General program
<syntaxhighlight lang="egl">
package programs;
program Empty_program type BasicProgram {}
function main()
end
end
</syntaxhighlight>
Rich UI handler (but also without 'initialUI = [ ui ], onConstructionFunction = start' it would have been valid.)
<pre>
package ruihandlers;
import com.ibm.egl.rui.widgets.Div;
handler Empty_program type RUIhandler {initialUI = [ ui ], onConstructionFunction = start}
ui Div{};
function start()
end
end
</pre>
=={{header|Eiffel}}==
A file called root.e:
<syntaxhighlight lang="eiffel">class
ROOT
create
make
feature
make
do
end
end</syntaxhighlight>
=={{header|Elena}}==
ELENA 4.x
<syntaxhighlight lang="elena">public program()
{
}</syntaxhighlight>
=={{header|Elixir}}==
<syntaxhighlight lang="elixir"></syntaxhighlight>
=={{header|Elm}}==
<syntaxhighlight lang="elm">
--Language prints the text in " "
import Html
main =
Html.text"empty"
</syntaxhighlight>
=={{header|EMal}}==
The empty script is valid and does nothing.
=={{header|Erlang}}==
An empty module:
<syntaxhighlight lang="erlang">-module(empty).</syntaxhighlight>
An empty Erlang script file (escript):
<syntaxhighlight lang="erlang">main(_) -> 1.</syntaxhighlight>
=={{header|ERRE}}==
<syntaxhighlight lang="text">
PROGRAM EMPTY
BEGIN
END PROGRAM
</syntaxhighlight>
=={{header|eSQL}}==
<syntaxhighlight lang="sql">CREATE COMPUTE MODULE ESQL_Compute
CREATE FUNCTION Main() RETURNS BOOLEAN
BEGIN
RETURN TRUE;
END;
END MODULE;</syntaxhighlight>
=={{header|Euphoria}}==
<syntaxhighlight lang="euphoria"></syntaxhighlight>
=={{header|F_Sharp|F#}}==
F# has an interactive mode and a compiled mode. The interactive interpreter will accept an empty file so the shortest valid program is an empty zero-length file with the .fsx extension.
<syntaxhighlight lang="fsharp"></syntaxhighlight>
An empty compiled program is:
<syntaxhighlight lang="fsharp">[<EntryPoint>]
let main args = 0</syntaxhighlight>
=={{header|Factor}}==
<syntaxhighlight lang="factor"></syntaxhighlight>
If you want to deploy a stand-alone application, that doesn't suffice though. Here's another version.
<syntaxhighlight lang="factor">IN: rosetta.empty
: main ( -- ) ;
MAIN: main</syntaxhighlight>
=={{header|Falcon}}==
<pre>></pre>
Prints an empty line.
<pre>>></pre>
Prints nothing.
=={{header|FALSE}}==
<syntaxhighlight lang="false"></syntaxhighlight>
=={{header|Fantom}}==
<syntaxhighlight lang="fantom">class Main
{
public static Void main () {}
}</syntaxhighlight>
=={{header|FBSL}}==
An empty string is a valid FBSL script in both uncompiled and compiled form. It won't however produce any visible output on the screen. The minimum implementations for the user to see the result are presented below:
'''Console mode:'''
<div style="overflow:auto;white-space:nowrap;background-color:ivory;border:1px dashed rgb(47, 111, 171); padding:12px"><b><code>
<span style="color:gray">#APPTYPE CONSOLE</span><br>
<span style="color:blue">PAUSE</span>
</code></b></div>
'''Output:'''
<div style="overflow:auto;white-space:nowrap;background-color:black;border:1px dashed rgb(167, 215, 249); padding:12px"><b><code>
<span style="color:white">Press any key to continue...</span>
</code></b></div>
'''Graphics mode:'''
<div style="overflow:auto;white-space:nowrap;background-color:ivory;border:1px dashed rgb(47, 111, 171); padding:12px"><b><code>
<span style="color:blue">SHOW</span>(<span style="color:darkblue">ME</span>) <span style="color:green">' all FBSL scripts are #APPTYPE GUI on default</span><br><span style="color:red">BEGIN EVENTS<br>END EVENTS</span>
</code></b></div>
'''Output:''' [http://i1240.photobucket.com/albums/gg490/FbslGeek/FBSL_ME.png GUI Form]
'''Minimum empty Dynamic Assembler block:'''
<div style="overflow:auto;white-space:nowrap;background-color:ivory;border:1px dashed rgb(47, 111, 171); padding:12px"><b><code>
<span style="color:red">DYNASM</span> Foo()
:<span style="color:blue">RET</span> <span style="color:green">; mandatory</span><br>
<span style="color:red">END DYNASM</span>
</code></b></div>
'''Minimum empty Dynamic C block:'''
<div style="overflow:auto;white-space:nowrap;background-color:ivory;border:1px dashed rgb(47, 111, 171); padding:12px"><b><code>
<span style="color:red">DYNC</span> Foo()
:<span style="color:blue">void</span> <span style="color:red">main</span>(<span style="color:blue">void</span>)<br>
:{
::<span style="color:blue">return</span>; <span style="color:green">// optional</span><br>
:}
<span style="color:red">END DYNC</span>
</code></b></div>
=={{header|Fermat}}==
<syntaxhighlight lang="fermat">;</syntaxhighlight>
=={{header|Fish}}==
Actually the shortest valid program is a space (not empty file!), which is an infinite loop, though. (It keeps looping around)
<syntaxhighlight lang="fish"> </syntaxhighlight>
An empty program is invalid; the interpreter will give an error.<br/>
The shortest program that will actually finish is a <tt>;</tt>, which will end the program immediately:
<syntaxhighlight lang="fish">;</syntaxhighlight>
=={{header|Forth}}==
<syntaxhighlight lang="forth"></syntaxhighlight>
For a Forth script to be used from a shell, you usually want the last command to be BYE in order to exit the interpreter when finished.
<syntaxhighlight lang="forth">bye</syntaxhighlight>
=={{header|Fortran}}==
<syntaxhighlight lang="fortran"> end</syntaxhighlight>
=={{header|FreeBASIC}}==
A completely empty program compiles and runs fine:
<syntaxhighlight lang="freebasic"></syntaxhighlight>
=={{header|friendly interactive shell}}==
Empty programs are valid, but are useless.
<syntaxhighlight lang="fishshell"></syntaxhighlight>
=={{header|Frink}}==
Empty programs are valid.
<syntaxhighlight lang="frink"></syntaxhighlight>
=={{header|FunL}}==
An empty text file is a valid FunL program that does nothing.
<syntaxhighlight lang="funl"></syntaxhighlight>
=={{header|Futhark}}==
Any Futhark program must have a <code>main</code> function. Alternatively, a Futhark library can be an empty file.
<syntaxhighlight lang="futhark">
let main = 0
</syntaxhighlight>
=={{header|FutureBasic}}==
<syntaxhighlight lang="futurebasic">HandleEvents</syntaxhighlight>
=={{header|Fōrmulæ}}==
{{FormulaeEntry|page=https://formulae.org/?script=examples/Empty_program}}
'''Solution'''
The following is the simplest expression: the Null expression. When it is run, it does not reduce to anything else, because there should not be rewriting rules for a null expression:
[[File:Fōrmulæ - Empty program 01.png]]
[[File:Fōrmulæ - Empty program 02.png]]
=={{header|Gambas}}==
<syntaxhighlight lang="gambas">
Public Sub Main()
End
</syntaxhighlight>
=={{header|Gecho}}==
Empty programs are valid.
<syntaxhighlight lang="gecho"></syntaxhighlight>
=={{header|Gema}}==
An empty program will copy input stream to output stream unchanged.
<syntaxhighlight lang="gema"></syntaxhighlight>
=={{header|Genyris}}==
<pre></pre>
=={{header|Global Script}}==
This program is intended for use with the [[HS Global Script]] and uses its syntax for imperative programs.
<syntaxhighlight lang="global script">λ _. impunit 〈〉</syntaxhighlight>
=={{header|Go}}==
<syntaxhighlight lang="go">package main
func main() { }</syntaxhighlight>
=={{header|Groovy}}==
<syntaxhighlight lang="groovy"></syntaxhighlight>
==={{header|GW-BASIC}}===
An empty text file is a correct GW-BASIC program that does nothing.
=={{header|Hare}}==
<syntaxhighlight lang="hare">export fn main() void = void;</syntaxhighlight>
=={{header|Haskell}}==
'''Standard:''' [[Haskell 98]]
The simplest possible program is a single module using the implicit module header "<tt>module Main(main) where</tt>", and defining the action <tt>main</tt> to do nothing:
<syntaxhighlight lang="haskell">main = return ()</syntaxhighlight>
The simplest possible module other than Main is one which contains no definitions:
<syntaxhighlight lang="haskell">module X where {}</syntaxhighlight>
=={{header|Haxe}}==
<syntaxhighlight lang="haxe">class Program {
static function main() {
}
}</syntaxhighlight>
Unlike most languages Haxe doesn't have arguments in the main function because it targets different platforms (some which don't support program arguments, eg: Flash or Javascript). You need to use the specific libraries of the platform you are targeting to get those.
=={{header|HicEst}}==
<syntaxhighlight lang="hicest">END ! looks better, but is not really needed</syntaxhighlight>
=={{header|HolyC}}==
An empty file is the simplest valid HolyC program and returns 0.
=={{header|HQ9+}}==
An empty file is a valid HQ9+ program that does nothing.
=={{header|HTML}}==
HTML 5, [http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html#optional-tags section 12.1.2.4 Optional tags], allows to omit ''html'', ''head'' and ''body'' tags. The implicit ''body'' element can be empty, but the implicit ''head'' element must contain a ''title'' element, says [http://www.whatwg.org/specs/web-apps/current-work/multipage/semantics.html#the-head-element section 4.2.1 The head element]. There seems no rule against an empty title. Therefore, the shortest correct HTML document is:
<syntaxhighlight lang="html5"><!DOCTYPE html><title></title></syntaxhighlight>
The shortest correct XHTML document is:
<syntaxhighlight lang="html5"><html xmlns="http://www.w3.org/1999/xhtml"><head><title /></head><body /></html></syntaxhighlight>
=={{header|Huginn}}==
<syntaxhighlight lang="huginn">main(){}</syntaxhighlight>
=={{header|i}}==
<syntaxhighlight lang="i">software{}</syntaxhighlight>
=={{header|Icon}} and {{header|Unicon}}==
<syntaxhighlight lang="icon">procedure main() # a null file will compile but generate a run-time error for missing main
end</syntaxhighlight>
=={{header|IDL}}==
<syntaxhighlight lang="idl">end</syntaxhighlight>
=={{header|Inform 7}}==
<syntaxhighlight lang="inform7">X is a room</syntaxhighlight>
Inform 7 is a language built for making interactive fiction, so a room needs to be defined for the player to start in.
=={{header|Intercal}}==
<syntaxhighlight lang="intercal">PLEASE GIVE UP</syntaxhighlight>
=={{header|Io}}==
<pre></pre>
=={{header|J}}==
<syntaxhighlight lang="j">''</syntaxhighlight>
It returns itself:
<syntaxhighlight lang="j"> '' -: ". ''
1</syntaxhighlight>
=={{header|Java}}==
{{works with|Java|1.5+}}
<syntaxhighlight lang="java">public class EmptyApplet extends java.applet.Applet {
@Override public void init() {
}
}</syntaxhighlight>
<syntaxhighlight lang="java">public class EmptyMainClass {
public static void main(String... args) {
}
}</syntaxhighlight>
The "..." basically means "as many of these as the programmer wants." Java will put multiple arguments into an array with the given name. This will work for any method where an array is an argument, but with a twist. A call can be made like this:
<syntaxhighlight lang="java">method(arg0, arg1, arg2, arg3)</syntaxhighlight>
All of the args will be put into an array in the order they were in the call.
{{works with|Java|1.0+}}
<syntaxhighlight lang="java">public class EmptyMainClass {
public static void main(String[] args) {
}
}</syntaxhighlight>
<syntaxhighlight lang="java">public class EmptyApplet extends java.applet.Applet {
public void init() {
}
}</syntaxhighlight>
@Override - Indicates that a method declaration is intended to override a method declaration in a superclass. If a method is annotated with this annotation type but does not override a superclass method, compilers are required to generate an error message. It's present from JDK 5.0 (1.5.0) and up.
Actually this is not strictly correct. The smallest possible correct program in Java is an empty source file.
=={{header|JavaScript}}==
The empty file is a valid program.
<pre></pre>
=={{header|Joy}}==
<syntaxhighlight lang="joy">.</syntaxhighlight>
A program in Joy is a sequence of zero or more factors followed by a full stop.
=={{header|Jq}}==
The “empty” filter ignores its input and outputs nothing.
<syntaxhighlight lang="jq">empty</syntaxhighlight>
=={{header|Julia}}==
Julia accepts an empty file as a program.
<syntaxhighlight lang="julia"></syntaxhighlight>
{{out}}
<pre>
$ wc empty_program.jl
0 0 0 empty_program.jl
$ julia empty_program.jl
$
</pre>
=={{header|K}}==
<syntaxhighlight lang="text"></syntaxhighlight>
=={{header|KonsolScript}}==
<syntaxhighlight lang="konsolscript">function main() {
}</syntaxhighlight>
=={{header|Kotlin}}==
<syntaxhighlight lang="kotlin">fun main() {}</syntaxhighlight>
=={{header|Lambdatalk}}==
An empty string is a valid program.
<syntaxhighlight lang="scheme"></syntaxhighlight>
=={{header|Lang}}==
The empty file is a valid program.
<pre></pre>
=={{header|Lang5}}==
<syntaxhighlight lang="lang5">exit</syntaxhighlight>
=={{header|Lasso}}==
Lasso will parse any file thrown at it. It will ignore everything except what's inside specific Lasso delimiters. Thus a valid program that did nothing, could be an empty file. Perhaps more correct would be a file that had the specific delimiters and then nothing inside them.
<syntaxhighlight lang="lasso">[]</syntaxhighlight>
<syntaxhighlight lang="lasso"><?lasso ?></syntaxhighlight>
<syntaxhighlight lang="lasso"><?= ?></syntaxhighlight>
=={{header|LaTeX}}==
<syntaxhighlight lang="latex">\documentclass{minimal}
\begin{document}
\end{document}</syntaxhighlight>
=={{header|LC3 Assembly}}==
The only thing you absolutely need is a directive telling the assembler to stop assembling code (which in this case it has not actually started doing).
<syntaxhighlight lang="lc3asm"> .END</syntaxhighlight>
=={{header|Liberty BASIC}}==
<syntaxhighlight lang="lb">end</syntaxhighlight>
=={{header|LilyPond}}==
According to the manual, all lilypond programs should contain a version statement expressing the minimum version number. If this is missing then a warning will be emitted.
<syntaxhighlight lang="lilypond">\version "2.6.12"</syntaxhighlight>
An input file should really have a basic structure as follows. The compiler automatically adds some of the structure components if they are not present in the source code. However, explicit definition should be used to prevent the compiler from creating unwanted contexts (which can cause side effects):
<syntaxhighlight lang="lilypond">\version "2.16.2"
\header {
}
\book {
\score {
\new Staff {
\new Voice {
}
}
\layout {
}
}
}</syntaxhighlight>
=={{header|Lingo}}==
"Program" doesn't really apply to Lingo. A Director projector (exe/app) doesn't have to contain any scripts/code. For scripts, the shortest possible code is:
<syntaxhighlight lang="lingo"></syntaxhighlight>
=={{header|Lisp}}==
Most Lisp dialects, including Common Lisp, will accept no text (no forms) as a valid program.
<syntaxhighlight lang="lisp"></syntaxhighlight>
=={{header|Little Man Computer}}==
[https://peterhigginson.co.uk/LMC/ V1.3 of Peter Higginson's implementation of Little Man Computer] accepts an empty program. If it is assembled then ran in it, a single fetch cycle is performed, which adds 1 to the program counter, which was previously 0, then the address register then the instruction register, both of which were previously blank, are changed to 0. Similar behavior is seen in [https://www.101computing.net/LMC/ 101 Computing's implementation of Little Man Computer], in which all CPU registers start at 00, then the program counter changes to 1, the MAR to 0 and the MDR and CIR to 000.
'''Assembly'''
<syntaxhighlight lang="little man computer"></syntaxhighlight>
'''Machine code'''
<syntaxhighlight lang="little man computer"></syntaxhighlight>
=={{header|Logo}}==
<syntaxhighlight lang="logo"></syntaxhighlight>
or end a standalone script with "bye"
<syntaxhighlight lang="logo">#! /usr/local/bin/logo
bye</syntaxhighlight>
=={{header|LSE}}==
<syntaxhighlight lang="lse"></syntaxhighlight>
=={{header|LSE64}}==
As with [[Forth]], an empty file is the shortest program. To exit the interpreter at the end of a loaded file:
bye
=={{header|Lua}}==
<syntaxhighlight lang="lua"></syntaxhighlight>
=={{header|M2000 Interpreter}}==
Open M2000 Environment, type Edit A and place one space or insert a new line, then exit pressing Esc and write Save Empty (press enter). Now write New (press enter). Now write Load Empty (press enter) and execute it: write A (press enter). Now you can close environment: write End (press enter).
To open file Empty.gsb, as text file (without loading to list of modules) use Edit "Empty.Gsb". To open it in notepad, we can use this command from M2000 console: win "notepad", dir$+"empty.gsb"
We can open explorer for dir$ (the m2000 user directory) using Win Dir$ (we can use paths without quotes if no space includes, so win c:\ open explorer to c:)
File saved as:
<syntaxhighlight lang="m2000 interpreter">
MODULE GLOBAL A {
}
</syntaxhighlight>
Because we make it in "level 0" (from console) this is a global module. A global module which loaded from console, or was a module loaded from a file at command line, when opening the environment, erased with an End, or a New, or a Start statement (reset of environment by software), or a Break by keyboard (although a dialog ask for proceed the breaking, the reset of environment) , or in some situation by using End Process from Task Manager.
If we wish to run it from command line (by clicking the file in explorer, and let m2000.exe open gsb files), we have to consider the first that this file not contain an execute statement, and that if we didn't use an input statement/function which need console, then console stay hide. To be sure that console open we have to use Show statement. To run A we have to include A at the last line (or append a line and write A). So we write in first line Show (press Esc to return to prompt) and save the file as Save Empty, A so we get this:
<syntaxhighlight lang="m2000 interpreter">
MODULE GLOBAL A {Show
}
A
</syntaxhighlight>
We can open it with Edit "empty.gsb" add some statements between A and block of module, to make some globals, say a DIM a(10) which stay there until the end of current interpreter run (interpreter may run multiple times simultaneously). All globals are globals for current interpreter only.
We can run empty.gsb now (supposed we save it as Save Empty, A), from explorer or using a command in M2000 console which opens another interpreter (and can feed it with some numbers or and strings, but this is another story):
<pre>
Use empty
</pre>
So now we see environment again, with open console and at prompt (execution done, and stay open because no End statement executed after the A, or inside module as Set End). Set used to send commands to prompt by code.
Finally this is the code in a file (say Empty.gsb) to open, display something, waiting for a key (now a Show automatic happen) and then finish. We have to write it, in M2000 editor, and save it using Save Empty, A or in any editor and save it as empty.gsb in your desired folder.
sav
<syntaxhighlight lang="m2000 interpreter">
MODULE GLOBAL A {
Print "Hello World"
a$=Key$
Set End
}
A
</syntaxhighlight>
We can save it scrabbled text using Save "empty" @, A (not readable, but environment can revert the process using a unique key)
(m2000 is open source so key is not a mystery, but you can make your own clone, and use own key)
=={{header|M4}}==
<syntaxhighlight lang="m4"></syntaxhighlight>
=={{header|Maple}}==
<syntaxhighlight lang="maple"></syntaxhighlight>
=={{header|Mathematica}} / {{header|Wolfram Language}}==
<syntaxhighlight lang="mathematica"></syntaxhighlight>
=={{header|MATLAB}}==
<syntaxhighlight lang="matlab"> function [varargout] = emptyprogram(varargin) </syntaxhighlight>
=={{header|Maxima}}==
<syntaxhighlight lang="maxima">block()$</syntaxhighlight>
=={{header|MAXScript}}==
An empty MAXScript file returns "OK" on execution
=={{header|MelonBasic}}==
<syntaxhighlight lang="melonbasic"></syntaxhighlight>
=={{header|Metafont}}==
<syntaxhighlight lang="metafont">end</syntaxhighlight>
=={{header|Microsoft Small Basic}}==
<syntaxhighlight lang="smallbasic"></syntaxhighlight>
{{out}}<pre></pre>
=={{header|min}}==
{{works with|min|0.19.3}}
<syntaxhighlight lang="min"></syntaxhighlight>
=={{header|MiniScript}}==
<syntaxhighlight lang="miniscript"></syntaxhighlight>
=={{header|MIPS Assembly}}==
===Linux===
This just exits the program with exit code 0 (exit_success)
<syntaxhighlight lang="mips">
.text
main: li $v0, 10
syscall
</syntaxhighlight>
===Nintendo 64===
In addition to a proper cartridge header, [[wp:Cyclic_redundancy_check|CRCs]], and footer, you'll need to write a value of <tt>8</tt> to address <tt>0xBFC007FC</tt> so that the cartridge can boot correctly. (Nintendo 64 is big-endian, so the 8 is actually stored at <tt>0xBFC007FF</tt>, but every example I've seen stores the value as a <code>uint32</code> so that's what I'm going with.)
After that, just enter an infinite loop and you're done.
<syntaxhighlight lang="mips">la $t0,0xBFC007FC
li $t1,8
sw $t1,0($t0)
halt:
nop ;not actually needed by real hardware, but Project 64 doesn't like infinite loops.
b halt
nop</syntaxhighlight>
=={{header|МК-61/52}}==
<syntaxhighlight lang="text">С/П</syntaxhighlight>
=={{header|ML/I}}==
<syntaxhighlight lang="ml/i"></syntaxhighlight>
=={{header|MMIX}}==
<syntaxhighlight lang="mmix"> LOC #100
Main TRAP 0,Halt,0 // main (argc, argv) {}</syntaxhighlight>
=={{header|Modula-2}}==
<syntaxhighlight lang="modula2">MODULE Main;
BEGIN
END Main.</syntaxhighlight>
=={{header|Modula-3}}==
<syntaxhighlight lang="modula3">MODULE Main;
BEGIN
END Main.</syntaxhighlight>
=={{header|MUMPS}}==
The empty file is a valid program.
<pre></pre>
==={{header|MSX Basic}}===
<syntaxhighlight lang="basic">10 rem</syntaxhighlight>
=={{header|N/t/roff}}==
{{works with|All implementations of TROFF}}
<syntaxhighlight lang="n/t/roff"></syntaxhighlight>
An empty input file is valid, but if the output is Postscript or PDF, most PDF viewers will suffer. However, that's the PDF viewer's fault; the typesetter is still okay with an empty file. If one wants grace for the PDF viewers, import a macro that, at the very least, defines some proper margins and pagination as in the following code:
{{works with|GNU TROFF|1.22.2}}
<syntaxhighlight lang="n/t/roff">.mso me.tmac</syntaxhighlight>
=={{header|Nanoquery}}==
Empty files are valid Nanoquery programs that do nothing.
<syntaxhighlight lang="nanoquery"></syntaxhighlight>
=={{header|Nemerle}}==
Compiles with warnings:
<syntaxhighlight lang="nemerle">null</syntaxhighlight>
Compiles without warnings (so, more correct):
<syntaxhighlight lang="nemerle">module Program
{
Main() : void
{
}
}</syntaxhighlight>
=={{header|NetRexx}}==
The following two samples both generate valid programs.
This minimal example requires that the file be named to match the class:
<syntaxhighlight lang="netrexx">class empty</syntaxhighlight>
This example will generate its class based on the file name:
<syntaxhighlight lang="netrexx">method main(args = String[]) static</syntaxhighlight>
=={{header|NewLISP}}==
<syntaxhighlight lang="newlisp">; </syntaxhighlight>
=={{header|Nim}}==
<pre></pre>
=={{header|Nit}}==
Although a Nit module (file) usually include a <tt>module</tt> declaration, an empty module is a valid Nit program.
<pre></pre>
=={{header|NS-HUBASIC}}==
<syntaxhighlight lang="ns-hubasic"></syntaxhighlight>
=={{header|Oberon-2}}==
<syntaxhighlight lang="oberon2">MODULE Main;
BEGIN
END Main.
</syntaxhighlight>
=={{header|Objeck}}==
<syntaxhighlight lang="objeck">bundle Default {
class Empty {
function : Main(args : String[]) ~ Nil {
}
}</syntaxhighlight>
=={{header|Objective-C}}==
{{works with|gcc|4.0.1}}
<syntaxhighlight lang="objc">int main(int argc, const char **argv) {
return 0;
}</syntaxhighlight>
The minimal ''empty'' Cocoa/OpenStep application, useful as life-support for many examples given at RosettaCode, is
<syntaxhighlight lang="objc">#import <Cocoa/Cocoa.h>
int main( int argc, const char *argv[] )
{
@autoreleasepool {
[NSApplication sharedApplication];
}
return 0;
}</syntaxhighlight>
=={{header|OCaml}}==
{{works with|Ocaml|3.09}}
<syntaxhighlight lang="ocaml">;;</syntaxhighlight>
Actually, the smallest possible correct program in OCaml is an empty source file.
=={{header|Octave}}==
An empty text file can be a valid empty program, but since Octave has the concept of "function file" (a file containing a single function; the file is automatically loaded when a function with the same name of the file, save for the extension, is called, and the first function present in the file is used), the name of the empty file matters. E.g. calling an empty file as <tt>isempty.m</tt> makes unusable the builtin <tt>isempty</tt> function.
=={{header|Odin}}==
<syntaxhighlight lang="odin">
package main
main :: proc() {}
</syntaxhighlight>
=={{header|Oforth}}==
An empty file is a valid oforth file
<syntaxhighlight lang="oforth">oforth empty.of</syntaxhighlight>
Without file, interpreter can just evaluate bye :
<syntaxhighlight lang="oforth">oforth --P"bye"</syntaxhighlight>
=={{header|Ol}}==
An empty file is considered the smallest runnable code.
A single comment can be considered a valid program that does nothing.
A file with any one-digit number ("0", "1", .. "9") or one-character function like "+", "-", etc.) is smallest non empty runnable code.
<syntaxhighlight lang="scheme">
0</syntaxhighlight>
=={{header|OOC}}==
The Compiler will accept an empty file:
<syntaxhighlight lang="ooc"></syntaxhighlight>
=={{header|OpenLisp}}==
We can run OpenLisp in shell mode with an empty program as follows.
This is for the Linux version of OpenLisp.
<syntaxhighlight lang="openlisp">
#!/openlisp/uxlisp -shell
()
</syntaxhighlight>
=={{header|Openscad}}==
<syntaxhighlight lang="openscad"></syntaxhighlight>
=={{header|OxygenBasic}}==
The smallest possible program is a single space character:
<syntaxhighlight lang="oxygenbasic">
</syntaxhighlight>
=={{header|Oz}}==
=== Accepted by compiler ===
The simplest 'program' that can be compiled is a file which contains a single expression.
<syntaxhighlight lang="oz">unit</syntaxhighlight>
Such a 'program' cannot be executed, though.
=== Standalone ===
The simplest standalone program is a root functor that does not define anything. ("Functors" are first-class modules.)
<syntaxhighlight lang="oz">functor
define
skip
end</syntaxhighlight>
=={{header|PARI/GP}}==
<syntaxhighlight lang="parigp"></syntaxhighlight>
=={{header|Pascal}}==
<syntaxhighlight lang="pascal">program ProgramName;
begin
end.</syntaxhighlight>
The first line is not necessary in modern Pascal dialects. With today's most compilers, the empty program is just:
<syntaxhighlight lang="pascal">begin end.</syntaxhighlight>
=={{header|PascalABC.NET}}==
<syntaxhighlight lang="delphi">
##
</syntaxhighlight>
=={{header|PepsiScript}}==
For typing:
<syntaxhighlight lang="pepsiscript">#include default-libraries
#author .
class .:</syntaxhighlight>
For importing:
While • is valid, the example below is the smallest possible "compiled" program that can be made normally.
•dl◘.◙
=={{header|Peri}}==
In the Peri language, a text file with a length of zero bytes is a correct program, but it does nothing.
Similarly, a text file that consists of all whitespace characters is also a correct program that does nothing.
=={{header|Perl}}==
The empty program is valid and does nothing but return a successful exit code:
<syntaxhighlight lang="perl"></syntaxhighlight>
Of course, this then requires you to specify the interpreter on the command line (i.e. <code>perl empty.pl</code>). So slightly more correct as a stand-alone program, is:
<syntaxhighlight lang="perl">#!/usr/bin/perl</syntaxhighlight>
The smallest possible Perl one-liner is <code>perl -e0</code>.
=={{header|Phix}}==
{{libheader|Phix/basics}}
An empty file is a valid program. When compiled however, it is far from empty as it contains most of the VM and a full run-time diagnostics kit (together about 202K).
<!--<syntaxhighlight lang="phix">(phixonline)--><!--</syntaxhighlight>-->
=={{header|PHP}}==
An empty text file is a correct PHP program that does nothing.
=={{header|Picat}}==
By default, Picat calls the <code>main/0</code> predicate:
<syntaxhighlight lang="picat">main.</syntaxhighlight>
{{out}}
<pre>$ picat empty_program.pi
</pre>
An shorter way is this program
<syntaxhighlight lang="picat">x.</syntaxhighlight>
but then an explicit goal at command line (<code>-g x</code>) must be given.
{{out}}
<pre>$ picat -g x empty_program2.pi
</pre>
=={{header|PicoLisp}}==
<syntaxhighlight lang="picolisp">(de foo ())</syntaxhighlight>
=={{header|Pike}}==
<syntaxhighlight lang="pike">int main(){}</syntaxhighlight>
=={{header|PIR}}==
The ''':main''' pragma indicates that a subroutine is the program's entry point. However, if a subroutine is the first (or only, which would also have the effect of making it the first) routine in the program, Parrot will use that. So we may comfortably omit it in this case.
<syntaxhighlight lang="pir">.sub empty_program
.end</syntaxhighlight>
=={{header|Pixilang}}==
Any text longer than 0 characters is valid, otherwise resulting in a "The file is empty or does not exist" error. In this example, a space character is used.
<syntaxhighlight lang="pixilang"> </syntaxhighlight>
=={{header|PL/I}}==
<syntaxhighlight lang="pl/i">s: proc options (main);
end;</syntaxhighlight>
=={{header|PL/SQL}}==
<syntaxhighlight lang="sql">BEGIN
NULL;
END;</syntaxhighlight>
=={{header|Plain English}}==
<syntaxhighlight lang="text">To run:</syntaxhighlight>
=={{header|plainTeX}}==
<syntaxhighlight lang="tex">\bye</syntaxhighlight>
=={{header|Pony}}==
<syntaxhighlight lang="pony">actor Main new create(e: Env) => ""</syntaxhighlight>
=={{header|Pop11}}==
Pop11 has two compilers, incremental and batch compiler. For the incremental compiler one can use just empty program text (empty file), or a file containing nothing but a comment, e.g.
<syntaxhighlight lang="pop11">;;; This is a valid Pop11 program that does absolutely nothing.</syntaxhighlight>
The batch compiler generates an executable which starts at a given entry point, so one should provide an empty function. If one wants program that works the same both with incremental compiler and batch compiler the following may be useful:
<syntaxhighlight lang="pop11">compile_mode :pop11 +strict;
define entry_point();
enddefine;
#_TERMIN_IF DEF POPC_COMPILING
entry_point();</syntaxhighlight>
Here the batch compiler will stop reading source before call to entry_point while incremental compiler will execute the call, ensuring that in both cases execution will start from the function entry_point.
=={{header|PostScript}}==
An empty file is a valid PostScript program that does nothing.
Following good programming practice, however, and to ensure that a PostScript printer will interpret a file correctly, one should make the first 4 characters of the file be
<syntaxhighlight lang="postscript">%!PS</syntaxhighlight>
If a particular version of the PS interpreter is needed, this would be included right there:
<syntaxhighlight lang="postscript">%!PS-2.0
% ...or...
%!PS-3.0
% etc</syntaxhighlight>
=={{header|PowerShell}}==
An empty script block. A script block is a nameless (lamda) function.
<syntaxhighlight lang="powershell">
&{}
</syntaxhighlight>
{{Out}}
<pre>
</pre>
=={{header|Processing}}==
An empty .pde sketch file.
<syntaxhighlight lang="processing"></syntaxhighlight>
When run this will produce a 200x200 inactive default gray canvas.
=={{header|ProDOS}}==
This is an acceptable program:
<syntaxhighlight lang="prodos">IGNORELINE</syntaxhighlight>
But also you could include a delimiter character recognized by the compiler/interpreter:
<syntaxhighlight lang="prodos">;</syntaxhighlight>
=={{header|Programming Language}}==
For typing:
<syntaxhighlight lang="programming language"></syntaxhighlight>
For importing:
At best, the code can have one line, which is empty. The smallest way to achieve this is to type nothing. However, this is the smallest possible "compiled" program that can be generated via the compiler:
[
=={{header|ProgressBASIC}}==
If you try to empty the memory and run it, you get this: [[File:Pbasic-no-memory-error.png|400px]]
Which is funny because the other BASIC-like languages support empty memory.
you can use the REM command and it will basicly do nothing if run the program. But the no memory error won't be emited
10 REM COMMENTS DO NOTHING
=={{header|PSQL}}==
<syntaxhighlight lang="sql">EXECUTE BLOCK
AS
BEGIN
END</syntaxhighlight>
=={{header|PureBasic}}==
An empty file is a correct PureBasic program that does nothing.
<syntaxhighlight lang="purebasic"></syntaxhighlight>
=={{header|Python}}==
An empty text file is a correct Python program that does nothing.
An empty file named <code>__init__.py</code> even has a structural purpose in Python of declaring that a directory is a [https://docs.python.org/3/tutorial/modules.html#packages Package].
=={{header|QUACKASM}}==
<syntaxhighlight lang="quackasm">1
QUIT</syntaxhighlight>
=={{header|Quackery}}==
An empty string or text file is a valid Quackery program that does nothing.
<syntaxhighlight lang="quackery"></syntaxhighlight>
{{out}}
<pre></pre>
=={{header|Quite BASIC}}==
<syntaxhighlight lang="quite basic"></syntaxhighlight>
=={{header|R}}==
An empty text file is a valid empty program
=={{header|Racket}}==
The following shows an empty program in Racket's default language. Other Racket languages may impose different conditions on the empty program.
<syntaxhighlight lang="racket">
#lang racket
</syntaxhighlight>
=={{header|Raku}}==
(formerly Perl 6)
The empty program is valid and does nothing but return a successful exit code:
<syntaxhighlight lang="raku" line></syntaxhighlight>
It is also possible to just specify that the program is written in Raku:
<syntaxhighlight lang="raku" line>use v6;</syntaxhighlight>
or even:
<syntaxhighlight lang="raku" line>v6;</syntaxhighlight>
=={{header|Raven}}==
An empty text file is an empty program.
=={{header|REBOL}}==
The header section is mandatory if you want it to be recognized as a REBOL program. It doesn't have to be filled in though:
<syntaxhighlight lang="rebol">REBOL []</syntaxhighlight>
=={{header|Retro}}==
An empty file is the smallest valid program.
<syntaxhighlight lang="retro"></syntaxhighlight>
=={{header|REXX}}==
An empty (or blank) file is a valid REXX program.
Some REXX implementations require a special comment [1<sup>st</sup> word in the comment must be REXX (in upper/lower/mixed) case]
<br>to distinguish from other types of scripting languages, and the comment must be the 1<sup>st</sup> line as well as the REXX word.
<br>But a null program (or a program with only blanks in it) in those other scripting languages is also considered a valid program.
===version 1===
This program can be empty (no characters), or a program with (only) one or more blanks.
<syntaxhighlight lang="rexx"></syntaxhighlight>
===version 2===
REXX on MVS/TSO requires REXX to be within a REXX comment that begins on the first line:
<syntaxhighlight lang="rexx">/*REXX*/</syntaxhighlight>
=={{header|Rhope}}==
{{works with|Rhope|alpha 1}}
Main(0,0)
|: :|
=={{header|Ring}}==
<syntaxhighlight lang="ring"></syntaxhighlight>
=={{header|Robotic}}==
<syntaxhighlight lang="robotic"></syntaxhighlight>
=={{header|RPL}}==
≪ ≫
=={{header|Ruby}}==
An empty file is a valid Ruby program. However, in order to make it runnable on *nix systems, a shebang line is necessary:
<syntaxhighlight lang="ruby">#!/usr/bin/env ruby</syntaxhighlight>
=={{header|Run BASIC}}==
<syntaxhighlight lang="runbasic">end ' actually a blank is ok</syntaxhighlight>
=={{header|Rust}}==
<syntaxhighlight lang="rust">fn main(){}</syntaxhighlight>
=={{header|Scala}}==
===Scala 2===
<syntaxhighlight lang="scala">object emptyProgram extends App {}</syntaxhighlight>
===Scala 3===
<syntaxhighlight lang="scala">@main def a = ()</syntaxhighlight>
=={{header|Scheme}}==
<syntaxhighlight lang="scheme"></syntaxhighlight>
=={{header|Scilab}}==
<syntaxhighlight lang="scilab"></syntaxhighlight>
=={{header|ScratchScript}}==
An empty program is invalid because it gives an [Err: Undefined] error. This behaviour still applies when the program isn't running. Due to this error, a program containing only an empty comment is the smallest possible valid program.
<syntaxhighlight lang="scratchscript">//</syntaxhighlight>
=={{header|sed}}==
A totally empty program is valid, and just copies the input unmodified. The same effect can be achieved with a single ''b'' command (which might be more convenient when called from the command line).
<syntaxhighlight lang="sh">sed "" input.txt
# vs
sed b input.txt</syntaxhighlight>
=={{header|Seed7}}==
<syntaxhighlight lang="seed7">$ include "seed7_05.s7i";
const proc: main is noop;</syntaxhighlight>
=={{header|Set lang}}==
<syntaxhighlight lang="set_lang"></syntaxhighlight>
=={{header|Sidef}}==
<syntaxhighlight lang="ruby"></syntaxhighlight>
=={{header|SimpleCode}}==
<syntaxhighlight lang="simplecode"></syntaxhighlight>
=={{header|Simula}}==
{{works with|SIMULA-67}}
<syntaxhighlight lang="simula">BEGIN
END</syntaxhighlight>
=={{header|Slate}}==
<syntaxhighlight lang="slate"></syntaxhighlight>
=={{header|Smalltalk}}==
<syntaxhighlight lang="smalltalk">[]</syntaxhighlight>
=={{header|SNOBOL4}}==
A valid program requires an '''end''' label. The shortest (virtually empty) program is then:
<syntaxhighlight lang="snobol">end</syntaxhighlight>
=={{header|SNUSP}}==
$#
'''$''' sets the instruction pointer (going right), and '''#''' halts the program (empty stack).
=={{header|Sparkling}}==
<syntaxhighlight lang="sparkling"></syntaxhighlight>
=={{header|SQL PL}}==
{{works with|Db2 LUW}}
With SQL only:
<syntaxhighlight lang="sql pl">
SELECT 1 FROM sysibm.sysdummy1;
</syntaxhighlight>
Output:
<pre>
db2 -t
db2 => SELECT 1 FROM sysibm.sysdummy1;
1
------------
1
1 record(s) selected.
</pre>
{{works with|Db2 LUW}}
With SQL PL:
<syntaxhighlight lang="sql pl">
--#SET TERMINATOR @
CREATE PROCEDURE myProc ()
BEGIN
END @
</syntaxhighlight>
Output:
<pre>
db2 -td@
db2 => CREATE PROCEDURE myProc ()
...
db2 (cont.) => END @
DB20000I The SQL command completed successfully.
</pre>
{{works with|Db2 LUW}} version 9.7 or higher.
With SQL PL:
<syntaxhighlight lang="sql pl">
BEGIN
END;
</syntaxhighlight>
Output:
<pre>
db2 -t
db2 => BEGIN
db2 (cont.) => END;
DB20000I The SQL command completed successfully.
</pre>
=={{header|SSEM}}==
A completely empty program—all store bits clear, just power the machine up and hit Run—is meaningful in SSEM code and even does something, although not something desirable:
<syntaxhighlight lang="ssem">00000000000000000000000000000000 0. 0 to CI jump to store(0) + 1
00000000000000000000000000000000 1. 0 to CI jump to store(0) + 1</syntaxhighlight>
Since the number in address 0 is 0, this is equivalent to
<pre> goto 1;
1: goto 1;</pre>
and has the effect of putting the machine into an infinite loop.
The smallest program that will terminate is:
<syntaxhighlight lang="ssem">00000000000001110000000000000000 0. Stop</syntaxhighlight>
=={{header|Standard ML}}==
<syntaxhighlight lang="sml">;</syntaxhighlight>
Actually, the smallest possible correct program in Standard ML is an empty source file.
=={{header|Stata}}==
Stata does not accept an empty program, so we have to do something. Here we only declare the minimum [http://www.stata.com/help.cgi?version version] of the interpreter for the program.
<syntaxhighlight lang="stata">program define nop
version 15
end</syntaxhighlight>
It's also possible to define an empty function in Mata.
<syntaxhighlight lang="stata">function nop() {}</syntaxhighlight>
=={{header|Suneido}}==
<syntaxhighlight lang="suneido">function () { }</syntaxhighlight>
=={{header|Swift}}==
<syntaxhighlight lang="swift"></syntaxhighlight>
=={{header|Symstatic}}==
The empty string is the smallest program.
=={{header|Symsyn}}==
<syntaxhighlight lang="symsyn"></syntaxhighlight>
=={{header|Tcl}}==
Nothing is mandatory in Tcl, so an empty file named <tt>nothing.tcl</tt> would be a valid "empty program".
<syntaxhighlight lang="tcl"></syntaxhighlight>
=={{header|TI-83 BASIC}}==
<syntaxhighlight lang="ti-basic"></syntaxhighlight>
Displays "Done". If an empty program isn't valid, there are numerous other one-byte solutions:
:
Disp
Return
Stop
=={{header|TI-83 Hex Assembly}}==
<syntaxhighlight lang="ti-basic">PROGRAM:EMPTY
:AsmPrgmC9</syntaxhighlight>
=={{header|TI-89 BASIC}}==
Prgm
EndPrgm
=={{header|Tiny BASIC}}==
An empty program works just fine.
<syntaxhighlight lang="tiny basic"></syntaxhighlight>
=={{header|Toka}}==
For interpreted code, nothing is required, although '''bye''' is necessary for an empty script to exit (rather than wait for the user to exit the listener). Hence:
bye
Or, for a directly runnable script:
#! /usr/bin/toka
bye
For compiled code, the simplest program is an empty quote:
[ ]
Again, to exit the listener, you will still need user input if this is not followed with '''bye'''.
=={{header|Trith}}==
<syntaxhighlight lang="trith"></syntaxhighlight>
=={{header|True BASIC}}==
<syntaxhighlight lang="qbasic">END</syntaxhighlight>
=={{header|TUSCRIPT}}==
<syntaxhighlight lang="tuscript">$$ MODE TUSCRIPT</syntaxhighlight>
=={{header|UNIX Shell}}==
{{works with|Bourne Shell}}
<syntaxhighlight lang="bash">#!/bin/sh</syntaxhighlight>
{{works with|Bourne Again SHell}}
<syntaxhighlight lang="bash">#!/bin/bash</syntaxhighlight>
{{works with|Korn SHell}}
<syntaxhighlight lang="ksh">#!/bin/ksh</syntaxhighlight>
=={{header|Unlambda}}==
i
(See how i plays so many roles in unlambda?)
=={{header|Ursa}}==
The Cygnus/X Ursa interpreter has no problems with empty files, so the shortest program is an empty file.
<syntaxhighlight lang="ursa"></syntaxhighlight>
=={{header|Vala}}==
<syntaxhighlight lang="vala">void main() {} </syntaxhighlight>
=={{header|VAX Assembly}}==
<syntaxhighlight lang="vax assembly">0000 0000 1 .entry main,0 ;register save mask
04 0002 2 ret ;return from main procedure
0003 3 .end main ;start address for linker</syntaxhighlight>
=={{header|VBA}}==
Same as Visual Basic, VB6, etc.
<syntaxhighlight lang="vb">Sub Demo()
End Sub</syntaxhighlight>
=={{header|VBScript}}==
An empty .vbs file is considered the smallest runnable code, but the following (a single apostrophe as comment marker) would also be acceptable (along with other non-executing instructions like <code>option explicit</code>.)
<syntaxhighlight lang="vb">'</syntaxhighlight>
=={{header|Verbexx}}==
An empty file is the smallest valid script, but running it does nothing.
<syntaxhighlight lang="verbexx"></syntaxhighlight>
=={{header|Verilog}}==
<syntaxhighlight lang="verilog">module main;
endmodule</syntaxhighlight>
=={{header|VHDL}}==
Compiled and simulated by Modelsim:
<syntaxhighlight lang="vhdl">entity dummy is
end;
architecture empty of dummy is
begin
end;</syntaxhighlight>
=={{header|Vim Script}}==
An empty file is a valid program.
=={{header|Visual Basic}}==
'''Works with:''' VB6
<syntaxhighlight lang="vb">Sub Main()
End Sub</syntaxhighlight>
=={{header|Visual Basic .NET}}==
{{works with|Visual Basic .NET|2005}}
<syntaxhighlight lang="vbnet">Module General
Sub Main()
End Sub
End Module</syntaxhighlight>
=={{header|V (Vlang)}}==
'''V (Vlang)''' can compile a 0 length, or whitespace only file as "empty", and "correct".
<pre></pre>
{{out}}
<pre>prompt$ ls -s blank.v
0 blank.v
prompt$ v run blank.v
prompt$ echo $?
0</pre>
A more reasonable example, that someone might guess was a V program, and not just an emptiness:
<syntaxhighlight lang="go">{}</syntaxhighlight>
For an even better chance at guessing that the file is meant as V source code:
<syntaxhighlight lang="go">module main
pub fn main() {}</syntaxhighlight>
=={{header|Wart}}==
<pre></pre>
=={{header|WDTE}}==
An empty 'file' is a valid WDTE script. That being said, WDTE has no inherent concept of scripts being in files, so a zero-length input may be a better description.
=={{header|WebAssembly}}==
{{libheader|WASI}}
<syntaxhighlight lang="webassembly">(module
;;The entry point for WASI is called _start
(func $main (export "_start")
)
)
</syntaxhighlight>
=={{header|Wee Basic}}==
<syntaxhighlight lang="wee basic"></syntaxhighlight>
=={{header|Wren}}==
<syntaxhighlight lang="wren"></syntaxhighlight>
=={{header|X86 Assembly}}==
{{works with|NASM|Linux}}
<syntaxhighlight lang="asm">section .text
global _start
_start:
mov eax, 1
int 0x80
ret</syntaxhighlight>
{{works with|MASM}}
<syntaxhighlight lang="asm">.386
.model flat, stdcall
option casemap:none
.code
start:
ret
end start</syntaxhighlight>
=={{header|XBasic}}==
{{works with|Windows XBasic}}
{{works with|Linux XBasic}}
<syntaxhighlight lang="qbasic">PROGRAM "Empty program"
DECLARE FUNCTION Entry ()
FUNCTION Entry ()
END FUNCTION
END PROGRAM</syntaxhighlight>
=={{header|XPL0}}==
An empty file compiles and builds an EXE file with a single RET instruction, but of course does nothing when executed.
<pre></pre>
=={{header|XQuery}}==
<syntaxhighlight lang="xquery">.</syntaxhighlight>
The dot selects the current context node and returns it unchanged.
=={{header|XSLT}}==
<syntaxhighlight lang="xslt"><?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<!-- code goes here -->
</xsl:stylesheet></syntaxhighlight>
Add other namespaces to the stylesheet attributes (like xmlns:fo="http://www.w3.org/1999/XSL/Format") if you use them.
Since XSLT is XML, and <code>transform</code> is a synonym for <code>stylesheet</code>, the example above can be minified to:
<syntaxhighlight lang="xslt"><transform xmlns="http://www.w3.org/1999/XSL/Transform" version="1.0"/></syntaxhighlight>
This stylesheet echoes the text content of an XML file. The shortest stylesheet without any output would be
<syntaxhighlight lang="xslt"><transform xmlns="http://www.w3.org/1999/XSL/Transform" version="1.0">
<template match="/" />
</transform></syntaxhighlight>
=={{header|xTalk}}==
{{works with|HyperCard}} {{works with|LiveCode}}
on startup
end startup
=={{header|XUL}}==
<syntaxhighlight lang="xul">
<?xml version="1.0"?>
</syntaxhighlight>
=={{header|Yabasic}}==
<syntaxhighlight lang="yabasic"></syntaxhighlight>
=={{header|Yorick}}==
An empty file is valid and does nothing.
<pre></pre>
=={{header|Z80 Assembly}}==
===Amstrad CPC, ZX Spectrum, etc.===
Most 8-bit computers work in a similar fashion: The BASIC interpreter acts as an operating system, and your entire program is essentially a subroutine that BASIC will <code>CALL</code>. If you "return" from your program the computer will go back to BASIC.
<syntaxhighlight lang="z80">ret</syntaxhighlight>
===Game Boy===
{{trans|Game Boy Advance}}
The Nintendo logo is loaded from the cartridge header, and the Game Boy's firmware won't boot the game without it. In addition, the firmware also reads a checksum of the cartridge contents and won't boot the game if it doesn't match the checksum stored in the header. So a truly "empty" program can't be run at all. Thus a minimum of a valid cartridge header is required for an empty program that the Game Boy can actually run.
The beginning of the cartridge header is a jump to the program's start.
<syntaxhighlight lang="z80">ProgramStart:
nop ;not sure if this is needed but Game Boy is somewhat buggy at times and the tutorials I used all did it
di ;disable interrupts
foo:
jp foo ;trap the program counter here. (Don't do this on a real Game Boy, you'll drain the batteries much faster than usual.)</syntaxhighlight>
=={{header|Zig}}==
<syntaxhighlight lang="zig">pub fn main() void {}</syntaxhighlight>
=={{header|zkl}}==
An empty file/string is valid.
<pre></pre>
<syntaxhighlight lang="zkl">c:=Compiler.Compiler.compileText("");
c() //--> Class(RootClass#)</syntaxhighlight>
=={{header|Zoea}}==
<syntaxhighlight lang="zoea">
program: empty
</syntaxhighlight>
=={{header|Zoea Visual}}==
[http://zoea.co.uk/examples/zv-rc/Empty_program.png Empty Program]
=={{header|Zoomscript}}==
For typing:
<syntaxhighlight lang="zoomscript"></syntaxhighlight>
For importing:
If nothing is entered into the "Import program" textbox, the code of the program that was already in the editor will remain.
¶0¶
=={{header|ZX Spectrum Basic}}==
:''See [[#BASIC|BASIC]]''
|