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Revision as of 16:08, 7 February 2003 by Ap (talk | contribs)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)A "hello world" program is a computer program that simply prints out "Hello, world!".
This is a traditional first program to write when learning a new programming language, and can be a useful sanity test to make sure that a language's compiler, development environment, and run-time environment are correctly installed.
While minimal test programs such as this existed since the development of programmable computers, the tradition of using "Hello, world!" as the test message was probably started by its use as an example program in the book The C Programming Language, by Brian Kernighan and Dennis Ritchie.
Here are some examples in different languages:
Console
with Ada.Text_Io; use Ada.Text_Io;
procedure Hello is
begin
Put_Line ("Hello, world!");
end Hello;
MODEL SMALL IDEAL STACK 100H
DATASEG
HW DB 'Hello, world!$'
CODESEG
MOV AX, @data
MOV DS, AX
MOV DX, OFFSET HW
MOV AH, 09H
INT 21H
MOV AX, 4C00H
INT 21H
END
10 PRINT "Hello, world!" 20 END
GET "LIBHDR"
LET START () BE
$(
WRITES ("Hello, world!*N")
$)
++++++++++>++.>+.+++++++..+++.>++.<< +++++++++++++++.>.+++.------.--------.>+.>.
#include <stdio.h>
int main(void) {
printf("Hello, world!\n");
return 0;
}
#include <iostream> using namespace std;
int main() {
cout << "Hello, world!" << endl;
}
class HelloWorldApp {
public static void Main() {
System.Console.WriteLine("Hello, world!");
}
}
IDENTIFICATION DIVISION. PROGRAM-ID. HELLO-WORLD.
ENVIRONMENT DIVISION.
DATA DIVISION.
PROCEDURE DIVISION. DISPLAY "Hello, world!". STOP RUN.
(format t "Hello world!~%")
- DOS batch
@echo off echo "Hello, world!"
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
."Hello, world!"
H
PLEASE DO ,1 <- #13 DO ,1 SUB #1 <- #238 DO ,1 SUB #2 <- #112 DO ,1 SUB #3 <- #112 DO ,1 SUB #4 <- #0 DO ,1 SUB #5 <- #64 DO ,1 SUB #6 <- #238 DO ,1 SUB #7 <- #26 DO ,1 SUB #8 <- #248 DO ,1 SUB #9 <- #168 DO ,1 SUB #10 <- #24 DO ,1 SUB #11 <- #16 DO ,1 SUB #12 <- #158 DO ,1 SUB #13 <- #52 PLEASE READ OUT ,1 PLEASE GIVE UP
public class Hello {
public static void main(String args) {
System.out.println("Hello, world!");
}
}
program Hello;
begin
writeln('Hello, world!');
end.
#!/usr/local/bin/perl print "Hello, world!\n";
<?php
print("Hello, world!");
?>
#!/usr/local/bin/pike
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;
#!/usr/local/bin/python print "Hello, world!"
#!/usr/bin/ruby print "Hello, world!"
- sed (requires at least one line of input)
sed -ne '1s/.*/Hello, world!/p'
Transcript show: 'Hello, world!'
#!/usr/local/bin/tcl puts "Hello, world!"
put "Hello, world!"
#!/bin/sh echo 'Hello, world!'
(display "Hello, world!") (newline)
TERM EQU 19 the MIX console device number
ORIG 1000 start address
START OUT MSG(TERM) output data at address MSG
HLT halt execution
MSG ALF "MIXAL"
ALF " HELL"
ALF "O WOR"
ALF "LD "
END START end of the program
Graphical User Interfaces
MsgBox "Hello, world!"
X11
using a program
xmessage 'Hello, world!'
using C++ and gtkmm 2
#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);
}
Java
import java.awt.*; import java.awt.event.*;
public class HelloFrame extends Frame {
HelloFrame(String title) {
super(title);
}
public void paint(Graphics g) {
super.paint(g);
java.awt.Insets ins = this.getInsets();
g.drawString("Hello, World!", ins.left + 25, ins.top + 25);
}
public static void main(String args )
{
HelloFrame fr = new HelloFrame("Hello");
fr.addWindowListener(
new WindowAdapter() {
public void windowClosing(WindowEvent e)
{
System.exit( 0 );
}
}
);
fr.setResizable(true);
fr.setSize(500, 100);
fr.setVisible(true);
}
}
Java applet
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
JavaScript is a scripting language used in HTML files. To demo this program Cut and Paste the following code into any HTML file.
<script language="javascript">
function helloWorld()
{
javascript: alert("Hello World");
}
</script>
<a href="javascript:this.location()"
onclick="javascript: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>
External Link
See also: Just another Perl hacker