"Hello, World!" program: Difference between revisions
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<< "Hello, World!" MSGBOX >> |
<< "Hello, World!" MSGBOX >> |
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=== [[SWT]] === |
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import org.eclipse.swt.widgets.*; |
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public class Main { |
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public static void main (String [] args) { |
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Display display = new Display (); |
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Shell shell = new Shell(display); |
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shell.open (); |
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while (!shell.isDisposed ()) { |
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if (!display.readAndDispatch ()) display.sleep (); |
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} |
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display.dispose (); |
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=== [[Visual Basic]] incl [[Visual Basic for Applications|VBA]] === |
=== [[Visual Basic]] incl [[Visual Basic for Applications|VBA]] === |
Revision as of 21:19, 13 August 2004
A "hello world" program is a computer program that simply prints out "Hello, world!" on a display device. It is used in many introductory tutorials for teaching a programming language and many students use it as their first programming experience in a language.
Such a program is typically one of the simpler programs possible in a computer language. Some are surprisingly complex, especially in some graphical user interface (GUI) contexts. Some others are surprisingly simple, especially those which rely heavily on a particular command line interpreter ("shell") to perform the actual output. In many embedded systems, the text may be sent to a one or two-line LCD display (and in yet other systems, a simple LED being turned on may substitute for "Hello world!").
A "hello world" program can be a useful sanity test to make sure that a language's compiler, development environment, and run-time environment are correctly installed. Configuring a complete programming toolchain from scratch to the point where even trivial programs can be compiled and run may involve substantial amounts of work. For this reason, a simple program is used first when testing a new tool chain.
While small test programs existed since the development of programmable computers, the tradition of using the phrase "Hello, world!" as the test message was influenced by an example program in the book The C Programming Language, by Brian Kernighan and Dennis Ritchie. The example program from that book prints "hello, world
" (i.e., no capital letters, no exclamation sign; those have entered the tradition later). However, the first known instance of the usage of "Hello world!" is in A Tutorial Introduction to the Language B, by Brian Kernighan. [1]
A collection of "hello world" programs written in various computer languages can serve as a very simple "Rosetta Stone" to assist in learning and comparing the languages. Keep in mind, however, that unless assembly language or similar very low-level (hardware-near) languages are involved, not much "computing" in the way of actual calculation, is usually exhibited.
Here are some examples in different languages:
Text user interface (TUI) (aka console, line-oriented)
WRITE "Hello World"
with Ada.Text_Io; use Ada.Text_Io; procedure Hello is begin Put_Line ("Hello, world!"); end Hello;
PROC main() WriteF('Hello, World!') ENDPROC
'Hello World'
Accumulator-only architecture: DEC PDP-8, PAL-III assembler
See the example section of the PDP-8 article.
First successful µP/OS combinations: Intel 8080/Zilog Z80, CP/M, RMAC assembler
bdos equ 0005H ; BDOS entry point start: mvi c,9 ; BDOS function: output string lxi d,msg$ ; address of msg call bdos ret ; return to CCP msg$: db 'Hello, world!$' end start
Accumulator + index register machine: MOS Technology 6502, CBM KERNAL, ca65 assembler
MSG: .ASCIIZ "Hello, world!" LDX #0 LDA MSG,X ; load initial char @LP: JSR $FFD2 ; chrout INX LDA MSG,X BNE @LP RTS
Accumulator/Index microcoded machine: Data General Nova, RDOS
See the example section of the Nova article.
MODEL SMALL IDEAL STACK 100H DATASEG MSG DB 'Hello, world!$' CODESEG MOV AX, @data MOV DS, AX MOV DX, OFFSET MSG MOV AH, 09H ; DOS: output ASCII$ string INT 21H MOV AX, 4C00H INT 21H END
TERM EQU 19 console device no. (19 = typewriter) ORIG 1000 start address START OUT MSG(TERM) output data at address MSG HLT halt execution MSG ALF "HELLO" ALF " WORL" ALF "D " END START end of program
General-purpose-register CISC: DEC PDP-11, RT-11, MACRO-11
.MCALL .REGDEF,.TTYOUT,.EXIT .REGDEF HELLO: MOV #MSG,R1 MOVB (R1),R0 LOOP: .TTYOUT MOVB +(R1),R0 BNE LOOP .EXIT MSG: .ASCIZ /HELLO, WORLD!/ .END HELLO
.title hello .psect data, wrt, noexe chan: .blkw 1 iosb: .blkq 1 term: .ascid "SYS$OUTPUT" msg: .ascii "Hello, world!" len = . - msg .psect code, nowrt, exe .entry hello, ^m<> ; Establish a channel for terminal I/O $assign_s devnam=term, - chan=chan blbc r0, end ; Queue the I/O request $qiow_s chan=chan, - func=#io$_writevblk, - iosb=iosb, - p1=msg, - p2=#len ; Check the status and the IOSB status blbc r0, end movzwl iosb, r0 ; Return to operating system end: ret .end hello
.program ADR R0,message SWI "OS_Write0" SWI "OS_Exit" .message DCS "Hello, world!" DCB 0 ALIGN
or the even smaller version (from qUE);
SWI"OS_WriteS":EQUS"Hello, world!":EQUB0:ALIGN:MOVPC,R14
BEGIN { print "Hello, world!" }
MS BASIC (traditional, unstructured)
10 PRINT "Hello, world!" 20 END
:Disp "Hello, world!"
:HelloWorld() :Prgm :Disp "Hello, world!" :EndPrgm
sub main print "Hello, World" end sub
Structured BASIC
print "Hello, world!" end
GET "LIBHDR" LET START () BE $( WRITES ("Hello, world!*N") $)
%TITLE 'HELLO_WORLD' MODULE HELLO_WORLD (IDENT='V1.0', MAIN=HELLO_WORLD, ADDRESSING_MODE (EXTERNAL=GENERAL)) = BEGIN LIBRARY 'SYS$LIBRARY:STARLET'; EXTERNAL ROUTINE LIB$PUT_OUTPUT; GLOBAL ROUTINE HELLO_WORLD = BEGIN LIB$PUT_OUTPUT(%ASCID %STRING('Hello World!')) END; END ELUDOM
#include <stdio.h> int main() { printf("Hello, world!\n"); return 0; }
using System; class HelloWorldApp { public static void Main() { Console.WriteLine("Hello, world!"); } }
#include <iostream> int main() { std::cout << "Hello, world!" << std::endl; }
.method public static void Main() cil managed { .entrypoint .maxstack 8 ldstr "Hello world." call void [mscorlib]System.Console::WriteLine(string) ret }
module hello Start :: String Start = "Hello, world"
PROC 0 WRITE Hello, World!
IDENTIFICATION DIVISION. PROGRAM-ID. HELLO-WORLD. ENVIRONMENT DIVISION. DATA DIVISION. PROCEDURE DIVISION. DISPLAY "Hello, world!". STOP RUN.
(format t "Hello world!~%")
int main() { printf("Hello, world!\n"); return 0; }
DCL batch
$ write sys$output "Hello, world!"
a hello world! . p
or like so:
echo -e 'a\nhello world!\n.\np'|ed echo -e 'a\nhello world!\n.\np'|ex
class HELLO_WORLD creation make feature make is local io:BASIC_IO do !!io io.put_string("%N Hello, world!") end -- make end -- class HELLO_WORLD
-module(hello). -export([hello_world/0]). hello_world() -> io:fwrite("Hello, world!\n").
puts(1, "Hello, world!")
type data = { first: string; second: string; } let myData = { first="Hello"; second="world"; } let _ = print_string myData.first; print_string " "; print_string myData.second; print_newline()
begin TOOL HelloWorld; includes Framework; HAS PROPERTY IsLibrary = FALSE; forward Hello; -- START CLASS DEFINITIONS class Hello inherits from Framework.Object has public method Init; has property shared=(allow=off, override=on); transactional=(allow=off, override=on); monitored=(allow=off, override=on); distributed=(allow=off, override=on); end class; -- END CLASS DEFINITIONS -- START METHOD DEFINITIONS ------------------------------------------------------------ method Hello.Init begin super.Init(); task.Part.LogMgr.PutLine('HelloWorld!'); end method; -- END METHOD DEFINITIONS HAS PROPERTY CompatibilityLevel = 0; ProjectType = APPLICATION; Restricted = FALSE; MultiThreaded = TRUE; Internal = FALSE; LibraryName = 'hellowor'; StartingMethod = (class = Hello, method = Init); end HelloWorld;
." Hello, world!" CR
PROGRAM HELLO WRITE(*,10) 10 FORMAT('Hello, world!') STOP END
println["Hello, world!"]
See also GUI section.
PUBLIC SUB Main() Print "Hello, world!" END
In the draw event of some object:
draw_text(x,y,"Hello World");
module HelloWorld (main) where main = putStr "Hello World\n"
program HelloWorld; functions { _main() { String("Hello, world!") |> GetStdOut(); } } end
(Handheld Hewlett-Packard RPN-based alphanumeric engineering calculators.)
01 LBLTHELLO 02 THELLO, WORLD 03 PROMPT
ON ENTER { "Hello, " "World!" & SAY }
"Hello world!" print
or
write("Hello world!\n")
See also GUI section.
public class Hello { public static void main(String[] args) { System.out.println("Hello, world!"); } }
(disassembler output of javap -c Hello.class)
public class Hello extends java.lang.Object { public Hello(); public static void main(java.lang.String[]); } Method Hello() 0 aload_0 1 invokespecial #1 <Method java.lang.Object()> 4 return Method void main(java.lang.String[]) 0 getstatic #2 <Field java.io.PrintStream out> 3 ldc #3 <String "Hello, world!"> 5 invokevirtual #4 <Method void println(java.lang.String)> 8 return
WriteLine "Hello, world!"
print [hello world!]
or
pr [Hello World!]
In mswlogo only
messagebox [Hi] [Hello World]
print "Hello, world!"
W "Hello, world!"
MODULE Hello; FROM Terminal2 IMPORT WriteLn; WriteString; BEGIN WriteString("Hello, world!"); WriteLn; END Hello;
MS-DOS batch
(with the standard command.com interpreter. The @ symbol is optional and prevents the system from repeating the command before executing it. The @ symbol must be omitted on versions of MS-DOS prior to 5.0.)
@echo Hello, world!
: main me @ "Hello, world!" notify ;
#import <Foundation/Foundation.h>
int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSLog(@"Hello, World!"); [pool release]; return 0; }
let _ = print_endline "Hello world!";;
See also GUI section.
PROC hello: PRINT "Hello, World" ENDP
(object-class request ^action) (startup (strategy MEA) (make request ^action hello) ) (rule hello (request ^action hello) --> (write |Hello World!| (crlf)) )
program Hello; begin writeln('Hello, world!'); end.
print "Hello, world!\n";
<?php echo "Hello, world!"; ?>
int main() { write("Hello, world!\n"); return 0; }
Test: procedure options(main); declare My_String char(20) varying initialize('Hello, world!'); put skip list(My_String); end Test;
'Hello world' =>
#include "colors.inc" camera { location <3, 1, -10> look_at <3,0,0> } light_source { <500,500,-1000> White } text { ttf "timrom.ttf" "Hello world!" 1, 0 pigment { White } }
write('Hello world'),nl.
print "Hello, world!"
or:
import sys sys.stdout.write("Hello, World\n")
REXX, NetRexx, and Object REXX
say "Hello, world!"
or:
say 'Hello, world!'
See also GUI section.
(On Hewlett-Packard HP-28, HP-48 and HP-49 series graphing calculators.)
<< CLLCD "Hello, World!" 1 DISP 0 WAIT DROP >>
See also GUI section.
puts "Hello, world!"
class HELLO_WORLD is main is #OUT+"Hello World\n"; end; end;
object HelloWorld with Application { Console.println("Hello, world!"); }
(display "Hello, world!") (newline)
(note: requires at least one line of input)
sed -ne '1s/.*/Hello, world!/p'
'Hello, World!' print.
Transcript show: 'Hello, world!'
print "Hello, world!\n";
OUTPUT = "Hello, world!" END
create table MESSAGE (TEXT char(15)); insert into MESSAGE (TEXT) values ('Hello, world!'); select TEXT from MESSAGE; drop table MESSAGE;
Or (e.g. Oracle dialect)
select 'Hello, world' from dual;
Or (e.g. MySQL dialect)
select 'Hello, world';
Or, more simply
print 'Hello, World.'
Or (for KB-SQL dialect)
select Null from DATA_DICTIONARY.SQL_QUERY FOOTER or HEADER or DETAIL or FINAL event write "Hello, World!"
RACINE: HELLO_WORLD. NOTIONS: HELLO_WORLD : ecrire("Hello, world!").
#OUTPUT Hello, world!
puts "Hello, world!"
put "Hello, world!"
Declare @Output varchar(16) Set @Output='Hello, world!' Select @Output or, simpler variations: Select 'Hello, world!' Print 'Hello, world!'
echo 'Hello, world!'
Graphical user interfaces (GUIs)
ActionScript (Macromedia flash mx)
trace ("hello, world")
display dialog "Hello, world!"
Or to have the OS synthesize it and literally say "hello world!"
say "Hello world!" -- comma left out because that would cause the synthesizer to pause and sound silly
#import <Cocoa/Cocoa.h>
@interface hello : NSObject {
}
@end
@implementation hello
-(void)awakeFromNib { NSBeep(); // we don't need this but it's conventional to beep when you show an alert NSRunAlertPanel(@"Message from your Computer", @"Hello, world!", @"Hi!", nil, nil); }
@end
ShowMessage("Hello, world!");
See also TUI section.
PUBLIC SUB Main() Message.Info("Hello, world!") END
GTK toolkit (in C++)
#include <iostream> #include <gtkmm/main.h> #include <gtkmm/button.h> #include <gtkmm/window.h> using namespace std; class HelloWorld : public Gtk::Window { public: HelloWorld(); virtual ~HelloWorld(); protected: Gtk::Button m_button; virtual void on_button_clicked(); }; HelloWorld::HelloWorld() : m_button("Hello, world!") { set_border_width(10); m_button.signal_clicked().connect(SigC::slot(*this, &HelloWorld::on_button_clicked)); add(m_button); m_button.show(); } HelloWorld::~HelloWorld() {} void HelloWorld::on_button_clicked() { cout << "Hello, world!" << endl; } int main (int argc, char *argv[]) { Gtk::Main kit(argc, argv); HelloWorld helloworld; Gtk::Main::run(helloworld); return 0; }
GTK 2.x (in Euphoria)
include gtk2/wrapper.e Info(NULL,"Hello","Hello World!")
See also TUI section.
import javax.swing.JOptionPane; public class Hello { public static void main(String[] args) { JOptionPane.showMessageDialog(null, "Hello, world!"); System.exit(0); } }
- Java applets work in conjunction with HTML files.
<HTML> <HEAD> <TITLE>Hello World</TITLE> </HEAD> <BODY> HelloWorld Program says: <APPLET CODE="HelloWorld.class" WIDTH=600 HEIGHT=100> </APPLET> </BODY> </HTML> import java.applet.*; import java.awt.*; public class HelloWorld extends Applet { public void paint(Graphics g) { g.drawString("Hello, world!", 100, 50); } }
JavaScript (aka ECMAScript) and JScript
- JavaScript is a client-side scripting language used in HTML files. The following code can be placed in any HTML file.
<script type="text/javascript"><!-- function helloWorld() { alert("Hello, world!"); } //--></script> <a href="#" onclick="helloWorld()">Hello World Example</a>
- An easier method uses JavaScript implicitly, calling the reserved alert function. Cut and paste the following line inside the <BODY> .... </BODY> HTML tags.
<a href="#" onclick="alert('Hello, world!')">Hello World Example</a>
- An even easier method involves using popular browsers' support for the virtual 'javascript' protocol to execute JavaScript code. Enter the following as an Internet address (usually by pasting into the address box):
javascript:alert('Hello, world!')
See also TUI section.
(On Psion Series 3 and later compatible PDAs.)
PROC guihello: ALERT("Hello, world!","","Exit") ENDP
Qt toolkit (in C++)
#include <qapplication.h> #include <qpushbutton.h> #include <qwidget.h> #include <iostream> class HelloWorld : public QWidget { Q_OBJECT public: HelloWorld(); virtual ~HelloWorld(); public slots: void handleButtonClicked(); QPushButton *mPushButton; }; HelloWorld::HelloWorld() : QWidget(), mPushButton(new QPushButton("Hello, World!", this)) { connect(mPushButton, SIGNAL(clicked()), this, SLOT(handleButtonClicked())); } HelloWorld::~HelloWorld() {} void HelloWorld::handleButtonClicked() { std::cout << "Hello, World!" << std::endl; } int main(int argc, char *argv[]) { QApplication app(argc, argv); HelloWorld helloWorld; app.setMainWidget(&helloWorld); helloWorld.show(); return app.exec(); }
MsgBox "Hello, world!"
See also TUI section.
(On Hewlett-Packard HP-48G and HP-49G series calculators.)
<< "Hello, World!" MSGBOX >>
import org.eclipse.swt.widgets.*;
public class Main {
public static void main (String [] args) {
Display display = new Display (); Shell shell = new Shell(display); shell.open (); while (!shell.isDisposed ()) { if (!display.readAndDispatch ()) display.sleep (); } display.dispose ();
}
}
Visual Basic incl VBA
MsgBox "Hello, world!"
Windows API (in C)
#include <windows.h> LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM); char szClassName[] = "MainWnd"; HINSTANCE hInstance; int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { HWND hwnd; MSG msg; WNDCLASSEX wincl; hInstance = hInst; wincl.cbSize = sizeof(WNDCLASSEX); wincl.cbClsExtra = 0; wincl.cbWndExtra = 0; wincl.style = 0; wincl.hInstance = hInstance; wincl.lpszClassName = szClassName; wincl.lpszMenuName = NULL; //No menu wincl.lpfnWndProc = WindowProcedure; wincl.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1); //Color of the window wincl.hIcon = LoadIcon(NULL, IDI_APPLICATION); //EXE icon wincl.hIconSm = LoadIcon(NULL, IDI_APPLICATION); //Small program icon wincl.hCursor = LoadCursor(NULL, IDC_ARROW); //Cursor if (!RegisterClassEx(&wincl)) return 0; hwnd = CreateWindowEx(0, //No extended window styles szClassName, //Class name "", //Window caption WS_OVERLAPPEDWINDOW & ~WS_MAXIMIZEBOX, CW_USEDEFAULT, CW_USEDEFAULT, //Let Windows decide the left and top positions of the window 120, 50, //Width and height of the window, NULL, NULL, hInstance, NULL); //Make the window visible on the screen ShowWindow(hwnd, nCmdShow); //Run the message loop while (GetMessage(&msg, NULL, 0, 0)) { TranslateMessage(&msg); DispatchMessage(&msg); } return msg.wParam; } LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { PAINTSTRUCT ps; HDC hdc; switch (message) { case WM_PAINT: hdc = BeginPaint(hwnd, &ps); TextOut(hdc, 15, 3, "Hello, world!", 13); EndPaint(hwnd, &ps); break; case WM_DESTROY: PostQuitMessage(0); break; default: return DefWindowProc(hwnd, message, wParam, lParam); } return 0; }
Or much more easy :
#include <windows.h> int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { MessageBox(NULL, "Hello World", "", MB_OK); return 0; }
See also TUI section.
require 'wxruby' class HelloWorldApp < Wx::App def on_init ourFrame = Wx::Frame.new(nil, -1, "Hello, world!").show ourDialogBox = Wx::MessageDialog.new(ourFrame, "Hello, world!", "Information:", Wx::OK|Wx::ICON_INFORMATION).show_modal end end HelloWorldApp.new.main_loop
<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"> <box align="center"> <label value="Hello, world!" /> </box> </window>
Document Formats
The following sequence of characters, expressed in hexadecimal notation (with carriage return and newline characters at end of sequence):
48 65 6C 6C 6F 2C 20 77 6F 72 6C 64 21 0D 0A
HTML 4.01 Strict
(Using UTF-8 character set.)
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <title>Hello, world!</title> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> <p>Hello, world!</p> </body> </html>
XHTML 1.1
(Using UTF-8 character set.)
Please note that this document must also be sent with the appropriate HTTP Header, most preferably "application/xhtml+xml", but it MAY also be sent as "application/xml" or "text/xml"; however it MUST NOT be sent as "text/html"; see XHTML Media Types for further info.
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> <head> <title>Hello, world!</title> </head> <body> <p>Hello, world!</p> </body> </html>
{\rtf1\ansi\deff0 {\fonttbl {\f0 Courier New;}} \f0\fs20 Hello, world! }
/Courier findfont 24 scalefont setfont 100 100 moveto (Hello world!) show showpage
- In executing the interpreter, one can simply write
(Hello world!) stack
Hello world \bye
See also
- Hello world program in esoteric languages
- Fibonacci number program
- Just another Perl hacker
- List of basic computer science topics