AQA GCSE Computer Science bitesize revision presentation, - Program flow control, Part 2

1. Program Flow Control 2

2. Recap
• Sequence, Selection and Iteration looked at in
Program Flow Control 1
• Shapes used :

3. Case
• Useful for showing a series of if..then..else
statements where more than 2 options exist
– ie what Lego shall I buy? would have a different
Lego model
• The True line always flows to the right and the
False line goes to the next decision

4. Case in action
Shall I
buy
Castle
Lego?
Shall I
buy Star
Wars
Lego?
Shall I
buy City
Lego?
Buy Castle Lego
Buy Star Wars Lego
Buy City LegoBuy no Lego
YES
NO
YES
YES
NO
NO

5. Do-while
• Used for containing a process in a loop until it
is completed

6. Do-while in action
Buy Cake
Do you
want
more?
NO
YES