JavaScript Math.max: Find a Value and Handle Empty or Invalid Inputs

The task

Get the maximum from a small sensor batch, then reject empty or nonfinite data before returning a result. Keep this value-only operation separate from selecting a sensor record.

Runnable Node 22 example

const assert = require('node:assert/strict');

assert.equal(Math.max(...[6, 14, 9]), 14);
assert.equal(Math.max(), -Infinity);
assert.equal(Number.isNaN(Math.max(6, NaN, 9)), true);
function maximum(values) {
  if (values.length === 0 || !Array.from(values).every(Number.isFinite)) return null;
  return Math.max(...values);
}
assert.equal(maximum([6, 14, 9]), 14);
assert.equal(maximum([]), null);
assert.equal(maximum([6, NaN]), null);
assert.equal(maximum(new Array(1)), null);
console.log(`maximum=${maximum([6, 14, 9])}; empty=${maximum([])}`);

Expected output and explanation

The built-in empty result is −Infinity, which is mathematically useful but may not be the intended output of a sensor summary. The wrapper deliberately uses null for no valid batch, preserving a distinction from an actual finite measurement.

NaN propagates through the unguarded maximum. The finite-value check prevents that result and also rejects infinities. Array.from materializes holes as undefined so a sparse input is rejected instead of being skipped by every. This rule assumes a list of numeric measurements, not textual values requiring a separate conversion policy.

Pitfall to check

Expanding a huge array into function arguments can exceed engine limits. For large datasets, use an explicit incremental maximum with an appropriate input check. Also decide a tie policy if the caller needs the associated record rather than just the number.