Using a List
Instead of typing the amounts of water directly into the repeat until loops, it’s a good idea to use variables. A list variable lets you keep all the numbers together in, you guessed it, a list!
Go to the Variables section of blocks and click Make a List.
Enter WaterAmounts as the name and click OK.
Your list will appear on the stage.
Click the + at the bottom of the list and type in the number 6. This is the number of litres for your first illustration, the running tap.
Removing an item
- If you want to remove items from the list, you can click on the item you want to delete, then click the little
xthat appears next to it.
Add another item for your second illustration for flushing the toilet. The value for this one is 6 as well.
You can untick the checkbox next to your list in the Variables section to hide it from the stage.
Now you will use the values from your list to tell the loop how many times to repeat.
Look for this block in the blocks for you list in Variables:
Find your repeat loop for the Tap, and plug in the above block instead of the number 6 you typed in earlier.
Do the same for the second repeat loop, the one for Toilet.
In the block you put into the second repeat loop, click on the 1 and change it by typing in the number 2.
How does it work?
The block
lets you select a thing from your list.
The number chooses which thing to select. It represents a place in the list. So item 1 is the first thing on the list, item 2 is the second, and so on.
This number is called the index.
Check that your loops look like this, and then run your code to test it.
You should see it do the same thing as before! The only difference is that now you’re getting the number of repeats from a list instead of having typed it directly into the repeat block.
So you’ve managed to replace one set of numbers with a list. How about doing the same with the sprites that match up with those numbers? You’ll do this in the next step!