Sensor Labels

Weather balloons report a temperature in degrees, or null when a sensor is offline. Write labelReadings(readings: (number | null)[]): string[] that turns each reading into a label:

null becomes "offline"
below 0 becomes "freezing"
0 up to and including 25 becomes "mild"
above 25 becomes "hot"

Check for null first. After that check, TypeScript knows the reading is a number.

Examples

labelReadings([null, -4, 18, 31])

→ ["offline", "freezing", "mild", "hot"]

labelReadings([0, 25, 25.5])

→ ["mild", "mild", "hot"]

solution.ts

TYPESCRIPT

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Tests

0 of 4 passing

•
one of each
labelReadings([null, -4, 18, 31])
expected ["offline", "freezing", "mild", "hot"]
•
edges
labelReadings([0, 25, 25.5])
expected ["mild", "mild", "hot"]
•
all quiet
labelReadings([null, null])
expected ["offline", "offline"]
•
no readings
labelReadings([])
expected []

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