35 lines
1.5 KiB
Markdown
35 lines
1.5 KiB
Markdown
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This is great. Each item can now take different amounts of time to be scanned, but when you have multiple cashiers,
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one can scan many "easy" items, while the other scans one slowly. So simply adding up the time won't cut it.
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To prepare the program for more than one cashier, this needs to change. To stay on the topics of enums we
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will use a construct known as a [finite-state-machine](https://en.wikipedia.org/wiki/Finite-state_machine).
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## Knowledge
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A finite-state-machine let's you easily define different behaviours depending on what state their are in.
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Basically you need a variable to track the state, in this case it is ``CurrentState`` and you need a way of
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implementing different behaviour based on the current state. For that you can simply use if statements.
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If you have more than one condition you want to test on, for example three different states,
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you can use the **else if** statement. This allows you to first test if one thing is true and, if is not,
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you can test for the second condition. You can chain as many else if statements as you want.
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if(condition1)
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{
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// gets executed if condition 1 is true
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}
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else if(condition2)
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{
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// gets executed if condition1 is false and condition2 is true
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}
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else
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{
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// gets executed if non of the conditions above are true
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}
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So our cashier has the state STATE_ready_for_item and STATE_scanning. These are represented as an enum.
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## Task
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Your task will be to implement the state-machine with an enum, such that while scanning
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you only increment the time-step by one.
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