Software Learning Process

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 <stdio.h>
             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;
 
             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);
             }

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 <stdio.h>
             #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

             % cat
             Hello, world.
             ^D

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