Hello World is a simple program that, when run, displays the message: Hello World . Fittingly, the Hello World program has long been the new programmer's induction into a myriad of programming languages. A project at the Association for Computing Machinery (ACM) of Louisiana Tech collected all the Hello World program examples they could find -- and discovered 204.
Here's what the Hello World program looks like in Pascal :
program Hello; begin (* Main *) writeln ('Hello, world!') end. (* Main *)The output should look like: Hello, world!
No one knows exactly why Hello World has stood the test of time so well. The most likely historical explanation is simply that a short program like Hello World once allowed the programmer to make sure that a language's compiler , development environment, and run-time environment were correctly installed. Because this involved a lot of work, a very simple program was used first to test things out. According to Wikipedia, the tradition of using the phrase "Hello, world" as the test message was influenced by an example program in the book "The C Programming Language", by Brian Kernighan and Dennis Ritchie.