High School/Jr.High

  10 PRINT "HELLO WORLD"
  20 END
First year in College

  program Hello(input, output)
    begin
      writeln('Hello World')
    end.
Senior year in College

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

  #include
  void main(void)
  {
    char *message[] = {"Hello ", "World"};
    int i;

    for(i = 0; i < 2; ++i)
      printf("%s", message[i]);
    printf("\n");
  }
Seasoned professional

  #include <iostream.h>
  #include <string.h>

  class string
  {
  private:
    int size;
    char *ptr;

  string() : size(0), ptr(new char[1]) { ptr[0] = 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);
  }
Apprentice Hacker

  #!/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;
Experienced Hacker

  #include
  #define S "Hello, World\n"
  main(){exit(printf(S) == strlen(S) ? 0 : 1);}
Seasoned Hacker

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

  % echo "Hello, world."
New Manager

  10 PRINT "HELLO WORLD"
  20 END
Middle 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
Senior Manager

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

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

Chief Executive 才不会进到shell里呢。

我啥时候能进化到
I need a "Hello, world." program by this afternoon.
就心满意足了