The Hello world program

Hello world program

A "Hello world" program is a computer program that outputs "Hello world" on a display device. Because it is typically one of the simplest programs possible in most programming languages, it is by tradition often used to illustrate to beginners the most basic syntax of a programming language, or to...

is a simple computer program

Computer program

A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 that prints (or displays) the string "Hello World". It is typically one of the simplest programs possible in almost all computer languages, and often used as first program to demonstrate a programming language. As such it can be used to quickly compare syntax differences between various programming languages. The following is a list of canonical hello world programs in many programming languages.

ActionScript 3.0

trace ("Hello World!");

or (if you want it to show on the stage)

package com.example
{
import flash.text.TextField;
import flash.display.Sprite;

public class Greeter extends Sprite
{
public function Greeter
{
var txtHello:TextField = new TextField;
txtHello.text = "Hello World";
addChild(txtHello);
}
}
}

ADA

with Ada.Text_Io;

procedure Hello_World is
begin
Ada.Text_Io.Put_Line("Hello World!");
end;

Adventure Game Studio Script

Display("Hello, World!");

or (if you want to draw it to the background surface)

DrawingSurface *surface = Room.GetDrawingSurfaceForBackground;
surface.DrawString(0, 100, Game.NormalFont, "Hello, World!");
surface.Release;

Algol 68

print("Hello world!")

Assembly Language - x86 DOS

The output file is 22 bytes.
14 bytes are taken by "Hello, world!$

Written by Stewart Moss - May 2006
This is a .COM file so the CS and DS are in the same segment

I assembled and linked using TASM

tasm /m3 /zn /q hello.asm
tlink /t hello.obj

.model tiny
.code
org 100h

main proc

mov ah,9 ; Display String Service
mov dx,offset hello_message ; Offset of message (Segment DS is the right segment in .COM files)
int 21h ; call DOS int 21h service to display message at ptr ds:dx

retn ; returns to address 0000 off the stack
; which points to bytes which make int 20h (exit program)

hello_message db 'Hello, World!$'

main endp
end main

Assembly Language - x86 Windows 32 bit

This program displays "Hello, World!" in a windows messagebox and then quits.

Written by Stewart Moss - May 2006

Assemble using TASM 5.0 and TLINK32

The ouput EXE is standard 4096 bytes long.
It is possible to produce really small windows PE exe files, but that
is outside of the scope of this demo.

.486p
.model flat,STDCALL
include win32.inc

extrn MessageBoxA:PROC
extrn ExitProcess:PROC
.data
HelloWorld db "Hello, World!",0
msgTitle db "Hello world program",0

.code
Start:
push MB_ICONQUESTION + MB_APPLMODAL + MB_OK
push offset msgTitle
push offset HelloWorld
push 0
call MessageBoxA

push 0
call ExitProcess
ends
end Start

AWK

BEGIN { print "Hello world!" }

BASIC

PRINT "Hello world!"

Batch File

@ECHO off
ECHO Hello World!
PAUSE
@ECHO on

brainfuck

+++++ +++++ initialize counter (cell #0) to 10
[ use loop to set the next four cells to 70/100/30/10
> +++++ ++ add 7 to cell #1
> +++++ +++++ add 10 to cell #2
> +++ add 3 to cell #3
> + add 1 to cell #4
<<<< - decrement counter (cell #0)
]
> ++ . print 'H'
> + . print 'e'
+++++ ++ . print 'l'
. print 'l'
+++ . print 'o'
> ++ . print ' '
<< +++++ +++++ +++++ . print 'W'
> . print 'o'
+++ . print 'r'
----- - . print 'l'
----- --- . print 'd'
> + . print '!'
> . print '\n'

C

1. include

int main(void)
{
printf("Hello world\n");
return 0;
}

C++

1. include

int main
{
std::cout << "Hello World!" << std::endl;
return 0;
}

C#

using System;
class ExampleClass
{
static void Main(string[] args)
{
Console.WriteLine("Hello, world!");
}
}

CFML (ColdFusion)

CF Script:


variables.greeting = "Hello, world!";
WriteOutput( variables.greeting );



CFML Tags:


#variables.greeting#

Clojure

Console version:


(println "Hello, world!")


GUI version:


(javax.swing.JOptionPane/showMessageDialog nil "Hello, world!")

COBOL

IDENTIFICATION DIVISION.
PROGRAM-ID. HELLO-WORLD.
PROCEDURE DIVISION.
DISPLAY 'Hello, world'.
STOP RUN.

D

import std.stdio;

void main
{
writeln("Hello World!");
}

Dart

main
{
print('Hello World!');
}

Delphi

{$APPTYPE CONSOLE}
begin
Writeln('Hello, world!');
end.

Erlang

io:format("~s~n", ["hello, world"])

F#

printfn "Hello World!"

Fortran

program hello
print *, "Hello World"
end program hello

Game Maker Language

str='Hello World'

//Using the show_message function:
show_message(str);

//Using the draw_text function:
draw_text(320,240,str);

Go

package main

import "fmt"

func main {
fmt.Println("Hello World!")
}

Groovy

println "Hello World!"

Haskell

main = print "Hello World!"

Io

"Hello world!" println

Java

public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello world!");
}
}

JavaScript

document.write('Hello world!');


or


alert('Hello world!');


or


console.log('Hello world!');


or (when using node.js)


var util=require('util');
util.puts('Hello world!');

Lisp

(print "Hello world!")

Lua

print("Hello World!")

Mathematica

Print["Hello World!"]

MATLAB

disp('Hello World!')

mIRC Script

echo -a Hello World!

ObjectiveC

1. import

int main(void)
{
printf("Hello, World!\n");
return 0;
}

OCaml

print_endline "Hello world!"

Opa

A "hello world" web server

Web server

Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....

:

server = Server.one_page_server("Hello", ( -> <>Hello world!))

Pascal

program HelloWorld;

begin
WriteLn('Hello world!');
end.

Perl 5

print "Hello World.";

Or

use v5.10;
say 'Hello World.';

PHP

echo "Hello, world";
?>

PL/SQL

SET SERVEROUTPUT ON;
BEGIN
DBMS_OUTPUT.PUT_LINE('Hello world!');
END;
/

PowerShell

Write-Host "Hello world!"

Prolog

main :- write('Hello world!'), nl.

Python 2

print 'Hello World'

Python 3

print("Hello World")

Racket

Trivial "hello world" program:

1. lang racket

"Hello, World!"

Running this program produces "Hello, World!". More direct version:

1. lang racket

(printf "Hello, World!\n")


A "hello world" web server

Web server

Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....

using Racket's web-server/insta language:

1. lang web-server/insta

(define (start request) (response/xexpr '(html (body "Hello World"))))}

RPL

<< "Hello World!" MSGBOX >>

RTL/2

TITLE Hello World;



LET NL=10;



EXT PROC(REF ARRAY BYTE) TWRT;



ENT PROC INT RRJOB;

    TWRT("Hello World!#NL#");

    RETURN(1);

ENDPROC;

Ruby

puts "Hello world!"

Scala

object HelloWorld extends App {
println("Hello world!")
}

Scheme

(display "Hello World")

Shell

echo Hello World

Simula

Begin
OutText ("Hello World!");
Outimage;
End;

Smalltalk

Transcript show: 'Hello, world!'.

SQL

SELECT 'Hello world!' FROM DUAL -- DUAL is a standard table in Oracle.
SELECT 'Hello world!' -- This will work in SQL Server.

Visual Basic

MsgBox "Hello, world!"

Visual Basic .NET

Module Module1
Sub Main
Console.WriteLine("Hello, world!")
End Sub
End Module

'non-console example:
Class Form1
Public Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
MsgBox("Hello, world!")
End Sub
End Class