Hello World: A Functional Computer Program

Hello World
Functional Computer Program

Hello World is a simple computer that prints or displays “Hello, World” on a computer monitor. The purpose of this program is to teach basic programming languages to new programmers and is used in tutorial programs.

It is the first program that many people who enter a computer programming curriculum learn. It simplicity allows novice programmers to be successful in writing a computer program.

Even seasoned computer programmers will use this code the first time they learn a new computer programming language.

The HelloWorld program is embedded when writing new programs to test the computer program’s structure and design. This is sometimes referred to as the sanity test.

If this simple line of code can be successfully processed by the new computer program, then the program language’s complier, development environment, and run-time environment are correctly installed.

Once an embedded program runs successfully, the remaining portion of the new computer program is written. This is much cheaper method for developing a new program, rather than writing the entire program and finding out that there are bugs in language or environment.

There are several variations of the Hello World program that alter the punctuation and phrase to test a new program language. These variations include:

No coma between Hello and World
Coma included between Hello and World
Exclamation mark after World
Quotation marks
Both Hello and World first letters are capitalized
No letters are capitalized
Enter phrase is italicized
Or a combination of any of the above

Here is what “HelloWorld” looks like in Pascal computer language:

   program Hello;
   begin     (* Main *)
      writeln ('Hello, world!')
   end.      (* Main *)

The output should look like: Hello, world!

Why HelloWorld has stood the test of time is unknown other than is simple and amusing. Just getting a computer language to display or print Hello World can be as complex as it is simple.

The computer program’s ability to process these two simple words will prove that the development process is correct.

When using Java Script, Hello World can be quite complex. Java is an object oriented language and all code must be contained within the class and defined.

In Java scrip Hellos World would like this in code:

<<HelloWorld.java>>=

public class HelloWorld

   class body

If you want to print Hello in Java Script you would write the code like this:

<<print greeting>>=

String message = hw.getMessage();

System.out.println(message);

The best way to learn HelloWorld is to learn to write your own computer programs that process the Hello World computer program.

One interesting thing that can be done with HelloWorld is by making it spin one time when the user clicks on the words HelloWorld.

First use the following program XML language:

<view width=”250” height=”150”>

<script src=”main.js” />

<img src=”background.png” />

<label x=”125” y=”70” align=”center” width=”250” size=”15” enabled=”true”

name=”mylabel” pinX=’125” pinY=”8”

onclick=”onTextClick( ) ; “>&Hello_World;</label>

Then you open the Java Script file – MyHelloWorld/main.js and write this new code:

//NEW code

function onTextClick( ) {

view.beginAnimation (doRotation, 0, 360, 500);

}

Function doRotation ( ) {