TheAlgorithms/JavaScript · error · Error

Invalid Input

Error message

Invalid Input

What it means

Thrown by `nthPrime(n)` (Project Euler #7) when `n < 1`. The function returns the n-th prime via trial counting, so n must be a positive integer. The message is generic ('Invalid Input') so check the source line for the exact condition. Non-number inputs bypass the guard.

Source

Thrown at Project-Euler/Problem007.js:15

import { PrimeCheck } from '../Maths/PrimeCheck.js'

/**
 * Find nth Prime Number
 *
 * P.S.(Project Euler - 007):
 * By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.
 * What is the 10001st prime number?
 *
 * @param {Number} n
 * @returns {Number} returns the nth prime number
 */
export const nthPrime = (n) => {
  if (n < 1) {
    throw new Error('Invalid Input')
  }

  let count = 0
  let candidateValue = 1
  while (count < n) {
    candidateValue++
    if (PrimeCheck(candidateValue)) {
      count++
    }
  }
  return candidateValue
}

View on GitHub (pinned to 5c39e87a9a)

Solutions

1. Validate `n >= 1` and is a finite integer upstream.
2. Coerce with `Number(n)` so string/undefined inputs are caught.
3. If 0 is semantically valid in your domain, decide on a fallback (e.g. return null) before calling.

Example fix

// before
nthPrime(req.query.n) // req.query.n could be '0' or undefined

// after
const n = Number(req.query.n)
if (!Number.isInteger(n) || n < 1) throw new RangeError('n must be a positive integer')
nthPrime(n)

const idx = Number(n)
if (!Number.isInteger(idx) || idx < 1) {
  throw new RangeError('n must be a positive integer')
}
nthPrime(idx)

const isPositiveInt = (x) => typeof x === 'number' && Number.isInteger(x) && x >= 1

When it happens

Trigger: Call `nthPrime(0)`, `nthPrime(-3)`. `nthPrime(1)` is valid and returns 2.

Common situations: Defaulting a 'which prime' field to 0, off-by-one in 0-indexed vs 1-indexed logic, or a request parameter parsed as 0 when empty.

Related errors

• Invalid Input
• Invalid input
• Invalid Input
• No natural numbers exist below 1
• Fibonacci sequence limit can't be less than 1

AI-assisted analysis of TheAlgorithms/JavaScript@5c39e87a9a (2026-08-13). Data as JSON: /api/errors/8feb593345dd605a. Report an issue: GitHub.