Hello World from RPG3 to RPG400 to RPGLE

What is an RPG language HELLO WORLD program?

A “Hello, World!” program is a simple computer program that outputs or displays the iconic phrase “Hello, World!” to a user. This humble program serves as a fundamental introduction to programming languages and illustrates their basic syntax. Let’s explore this tradition further:

The “Hello, World!” program typically accomplishes the following:

• It outputs or displays the message “Hello, World!” to the screen (often the console).
• It ignores any user input.

Why is it significant?

• For beginners learning a new programming language, writing a “Hello, World!” program is often their first step.
• It acts as a sanity check to ensure that the software intended to compile or run source code is correctly installed and operational.
• The tradition of using this phrase as a test message dates back to the 1978 book “The C Programming Language” by Brian Kernighan and Dennis Ritchie1.
• However, variations of this phrase have been used even earlier in other programming languages.

Here’s a classic example of a “Hello, World!” program in the IBM System38 RPG/3 language:

     C           'HELLO'   DSPLY
     C                     RETRN

Or the same program in the IBM AS400 RPG/400 language:

     C     'Hello World' DSPLY
     C                   RETURN

Or the same program in the modern IBM i free format RPG ILE language:

**free
dsply 'Hello World';
return;

I recently recorded a short series of videos coding these examples, trying to help any new, beginner, noob programmers out there. Don’t watch these if you are offended by random mutterings, stupid jokes, fat fingered typing, bad hair or silly coding examples: