The first usable program presented in the original Kernigan and Ritchie book on the C Programming Language was one that when run, would output the text: "Hello World" to the screen or printer. Here is a list of how various people would write the same application:
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"); }
All the way through: Seasoned professional, Master Programmer, Apprentice Hacker, Experienced Hacker, Seasoned Hacker and Guru Hacker. The list ends with these three:
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 -----------------