Page 237 - Learn To Program With Scratch

Name

Scope

Select the Data
palette and click
this button.

Figure 9-2: Creating a list in Scratch is similar to creating a variable .

List name. Use the checkbox to show or
hide the list’s monitor on the Stage.
Add a new item to the end of the list.
Remove the item at the specified index.
Insert an item at the specified index.

Replace the item at the specified index.
Return the item at the specified index.
Return the number of items in the list.
Does the list contain the specified item?
Show the list’s monitor on the Stage.

Hide the list’s monitor on the Stage.
Figure 9-3: Command and function blocks that you can use with lists

When a new list is created, Scratch also shows the list’s monitor on
the Stage, as illustrated in Figure 9-4. The list will initially be empty, so its
length starts at 0. You can use this monitor block to add entries to your list
as you design a program.

List name
Click this button to add
items to the list.
List currently has zero
items.
Drag this corner to change
the monitor’s size.

Figure 9-4: The monitor of a newly created list
is shown on the Stage .

If you know the data that you want to store in the list (as is the case for
our dayList), you can add it to the list at this point. Figure 9-5 shows how you
can add days to the dayList using its monitor.

Lists 215

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