TheAlgorithms/JavaScript · error · Error

Number must be greater than zero.

Error message

Number must be greater than zero.

What it means

The mobiusFunction computes the Mobius function mu(n): returns 0 if n has repeated prime factors, 1 if even count of factors, -1 if odd. Requires n > 0 for valid prime factorization. Important: PrimeFactors(number) is called at line 24 BEFORE the guard at line 25, so for non-positive input PrimeFactors may throw its own error first.

Source

Thrown at Maths/MobiusFunction.js:26

 *   μ(n) = 0 if n has a squared prime factor.
 */

/**
 * @function mobiusFunction
 * @description -> This method returns μ(n) of given number n
 * returns 1 when number is less than or equals 1
 * or number has even number of prime factors
 * returns 0 when number has repeated prime factor
 * returns -1 when number has odd number of prime factors
 * @param {Integer} number
 * @returns {Integer}
 */

import { PrimeFactors } from './PrimeFactors.js'
export const mobiusFunction = (number) => {
  const primeFactorsArray = PrimeFactors(number)
  if (number <= 0) {
    throw new Error('Number must be greater than zero.')
  }
  return primeFactorsArray.length !== new Set(primeFactorsArray).size
    ? 0
    : primeFactorsArray.length % 2 === 0
    ? 1
    : -1
}

View on GitHub (pinned to 5c39e87a9a)

Solutions

1. Pass a positive integer to mobiusFunction.
2. Guard n > 0 before calling to control which error surfaces.
3. Filter zero and negative values from data streams upstream.

Example fix

// before
mobiusFunction(n)
// after
if (!Number.isInteger(n) || n <= 0) throw new RangeError('n must be a positive integer')
mobiusFunction(n)

if (!Number.isInteger(number) || number <= 0) {
  throw new RangeError('number must be a positive integer')
}
mobiusFunction(number)

const isPositiveInteger = (n) => typeof n === 'number' && Number.isInteger(n) && n > 0

When it happens

Trigger: Calling mobiusFunction(0) or mobiusFunction(-1). Any non-positive integer triggers this error (or potentially an earlier error from PrimeFactors).

Common situations: Zero from uninitialized variables, negative inputs from subtraction, or data containing sentinel zero values.

Related errors

• Number must be greater than zero.
• Number must be greater than zero.
• Number must be greater than zero.
• Expected a valid real number
• Index cannot be Negative

AI-assisted analysis of TheAlgorithms/JavaScript@5c39e87a9a (2026-08-13). Data as JSON: /api/errors/5ce6a1285c5db11e. Report an issue: GitHub.