What this snippet does
A finite state machine makes all valid transitions explicit — any illegal event throws instead of causing silent corruption.
Expected output
red --[go]--> green green --[slow]--> yellow yellow --[stop]--> red
Why practise typing this
Typing design patterns code builds muscle memory for the symbols and indentation JavaScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
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