It's a kind of tradition. When a programer installs a compiler of a language he doesn't know (or an IDE - an interactive environment for development) he likes to do a little program that writes "Hello World!".

This before to know anything about the language, only copying and pasting some lines of code.

You will do it now!

Open the Croquet application.

Type (or copy and paste - right click over the window and use paste(v)) this code inside the Workspace:

|win|
win := SystemWindow new. "Creating a window"
win setLabel: 'HELLO WORLD !'.
win setWindowColor: Color blue.
win openInWorldExtent: 400@200.

CODE COMMENTS:

Here you are seeing, for the first, time MANY new things (we will explain all, in details, soon):

• 1 - how we define a variable (win).
• 2 - how we create an object-refrence of a Class (using new).
• 2a - how we use methods of this Class (setLabel etc.). Doesn't have a point like in Java.
• 3 - the signal to do an assignment (twopoints+equal);
• 4 - how we make a comentary (quotation marks);
• 5 - how we define an string (apostrophes);
• 6 - how we finalize a statement (point);
• 7 - after the two-points we have the parameter of a function, that can be an object (Color blue);
• 8 - we can have 2 parameters linked by "@".

Clicking the left button of the mouse drag the pointer over all the lines in the Workspace- they will have a green background.

Do an "accept" rightclicking over the Workspace. The list of commands appear where the pointer is. After, click : "do it" .

Our empty blue window having the title "HELLO WORLD!" appears! (I hope...)

Click in the figure of the main window (left-down) to go back to it.

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