Operation Manual

Enter this section now by clicking Control, and then drag the top entry—marked when [flag icon] clicked—and place it
just above the purple say brick (see Figure 10-3). If you drop it close enough, it should automatically join to the existing brick
like a jigsaw piece.
Figure 10-3: A Control block joined to a Looks block in Scratch
This concept of connecting multiple bricks together is the heart of Scratch. If you look at the Control brick you just placed, you’ll
see there’s no connecting hole at the top. This means that you can’t stack another brick on top, because this Control brick is
designed to trigger a series of other bricks directly and must come at the start of a stack. The bottom of the say brick,
meanwhile, has a connector that fits into the top of other bricks, which indicates that more bricks can be placed underneath.
With the two bricks in place, click the green flag icon at the top-right of the screen again. This time, a speech bubble will appear
from the cat’s mouth (see Figure 10-4), and the Hello World program is complete.
Before moving on to the next example, take the time to save your work using the File menu. Scratch is designed to have a single
project open at a time, so if you create a new blank file, the current file will be closed to make room. Don’t worry if you forget
about this when you go to create a new file—if there are unsaved changes in the existing file, Scratch will prompt you to save
these changes before closing it.
Figure 10-4: The Hello World program executing in Scratch