Hello World


Hier ein paar Methoden, wie man das allseits bekannte „Hello World“ – Programm implementieren kann.

Die Evolution eines Programmierers

Gymnasium

10 PRINT "HELLO WORLD"
20 END

Erstes Jahr Uni

program Hello(input, output)
begin
writeln('Hello World')
end.

Letztes Jahr Uni

(defun hello
(print
(cons 'Hello (list 'World))))

Frisch im Berufsleben

#include <stdio.h>
void main(void)
{
  char *message[] = {"Hello ", "World"};
  int i;
  for(i = 0; i < 2; ++i)
  printf("%s", message[i]);
  printf("\n");
}

Berufserfahren

#include <iostream.h>
#include <string.h>
class string
{
  private:
  int size;
  char *ptr;
  public:
    string() : size(0), ptr(new char('\0')) {}
    string(const string &s) : size(s.size)
    {
      ptr = new char[size + 1];
      strcpy(ptr, s.ptr);
    }
    ~string()
    {
      delete [] ptr;
    }
    friend ostream &operator <<(ostream &, const string &);
    string &operator=(const char *);
  };
  ostream &operator<<(ostream &stream, const string &s)
  {
    return(stream << s.ptr);
  }
  string &string::operator=(const char *chrs)
  {
    if (this != &chrs)
    {
      delete [] ptr;
      size = strlen(chrs);
      ptr = new char[size + 1];
      strcpy(ptr, chrs);
    }
    return(*this);
  }
  int main()
  {
    string str;
    str = "Hello World";
    cout << str << endl;
    return(0);
  }
}

Hacker-Lehrling

#!/usr/local/bin/perl
$msg="Hello, world.\n";
if ($#ARGV >= 0) {
while(defined($arg=shift(@ARGV))) {
$outfilename = $arg;
open(FILE, ">" . $outfilename) || die "Can't write $arg: $!\n";
print (FILE $msg);
close(FILE) || die "Can't close $arg: $!\n";
}
} else {
print ($msg);
}
1;

Erfahrener Hacker

#include <stdio.h>
#define S "Hello, World\n"
main(){exit(printf(S) == strlen(S) ? 0 : 1);}

Profi-Hacker

% cc -o a.out ~/src/misc/hw/hw.c
% a.out

Hacker-Guru

% cat
Hello, world.
^D

Neuer Manager

10 PRINT "HELLO WORLD"
20 END

Normaler Manager

mail -s "Hello, world." bob@b12
Bob, could you please write me a program that prints "Hello, world."?
I need it by tomorrow.
^D

Erfahrener Manager

% zmail jim
I need a "Hello, world." program by this afternoon.

Der Chef persönlich

% letter
letter: Command not found.
% mail
To: ^X ^F ^C
% help mail
help: Command not found.
% damn!
!: Event unrecognized