think49/get-primes.js

## get-primes.js
/**
 * get-primes.js
 * Get a prime list.
 *
 * @version 1.0.1
 * @author think49
 * @url https://gist.github.com/675313
 * @license http://www.opensource.org/licenses/mit-license.php (The MIT License)
 */

function getPrimes (length) {
  var i, number, primes, prime, perfectPower, primeLength;

  /** Check a natural number */
  if (length < 1 || length % 1 !== 0) {
    return [];
  }

  primes = [2];
  primeLength = primes.length;
  number = 3;

  /** Eratosthenes' sieve */
  while (length > primeLength) {
    i = 0;

    do {
      prime = primes[i++];
      perfectPower = prime * prime;
    } while (number > perfectPower && number % prime !== 0);


    if (number < perfectPower) {
      primeLength = primes.push(number);
    }
    number += 2;
  }

  return primes;
}
	/**
	* get-primes.js
	* Get a prime list.
	*
	* @version 1.0.1
	* @author think49
	* @url https://gist.github.com/675313
	* @license http://www.opensource.org/licenses/mit-license.php (The MIT License)
	*/

	function getPrimes (length) {
	var i, number, primes, prime, perfectPower, primeLength;

	/** Check a natural number */
	if (length < 1 \|\| length % 1 !== 0) {
	return [];
	}

	primes = [2];
	primeLength = primes.length;
	number = 3;

	/** Eratosthenes' sieve */
	while (length > primeLength) {
	i = 0;

	do {
	prime = primes[i++];
	perfectPower = prime * prime;
	} while (number > perfectPower && number % prime !== 0);


	if (number < perfectPower) {
	primeLength = primes.push(number);
	}
	number += 2;
	}

	return primes;
	}