Page 188 - Learn To Program With Scratch

sum count
0 2
+
2 4
+
6 6
+
12 8
+
20 10
... ...
Figure 7-14: This script finds the sum of all even integers from 2 to 20 .

This script starts by initializing the sum variable to 0 and the count
variable to 2, and then enters a conditional loop that repeats until count
exceeds 20. Each time the loop iterates, the value of count is added to the
current sum and the count variable is increased by 2 to get the next even
integer in the sequence. Predict the output of this script then run it to
check your answer.

non-integer rePeat count

Non-Integer What do you think would happen if you asked Scratch to repeat a loop
RepeatCount .sb2 2 .5 times? The three examples shown below demonstrate how Scratch
handles non-integer repeat counts .

Of course, there is no such thing as “repeat 2 .5 times,” but Scratch doesn’t
prevent you from entering such values . Rather than giving an error message,
Scratch automatically rounds a decimal repeat count to its nearest integer .

166 Chapter 7
www.it-ebooks.info