# Exercise 04: Define a useful contract

Use a copy of examples/04.

## A. Predict
Compare `const a = seatLabel(0)` with `const b = console.log("Full")`. Which variable holds useful label text, and why?

## B. Improve
Add the singular case so seatLabel(1) returns “1 place available”. Keep the negative and zero cases. Verify -1, 0, 1 and 2.

## C. Transfer
Write `canFit(available, requested)` that returns true only when requested is a whole number at least 1 and no greater than available. Assume available is a nonnegative integer. Test (4, 2), (2, 3), (4, 0), (4, 1.5). Hint: Number.isInteger checks whole numbers.

## Evidence
A four-row input/output table and your function. Explain one local name that cannot be used outside the function.

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