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Numbers

Aggregates and range maths over plain numbers — sum, average, rounding to a fixed precision, clamping, percentage formatting. roundTo is the usual Math.round(n * 10 ** d) / 10 ** d, which is right for display but still bound by float representation, so keep money in integer minor units or a decimal library. Randomness lives in random, not here — and for anything an attacker should not be able to predict, use crypto or security instead.

import { sum, average, roundTo, clamp, formatPercent } from '@rtorcato/js-common/numbers'

sum([1, 2, 3, 4, 5])      // 15
average([10, 20, 30])     // 20
roundTo(3.14159, 2)       // 3.14
clamp(42, 0, 10)          // 10
formatPercent(0.1234, 1)  // "12.3%"

See also​

  • currency — price formatting, parsing and currency codes
  • random — random ints, floats, strings and array picks