isPrime.js

/**
 * 判断质数
 * @param {Nubmer} nubmer
 * @return {Boolean}
 */
function isPrime (number) {
  let isNumber = "number" === typeof number;
  let isInteger = isNumber && 0 === number % 1;
  let isNatural = isInteger && -1 < number;
  if (!isNatural || 2 > number) { return false; }
  let maxFactor = Math.sqrt(number);
  for (let factor = 2; factor <= maxFactor; factor++) {
    if (0 === number % factor) { return false; }
  }
  return true;
}

test.js

for (let number = 2; number < 99; number++) {
  if (isPrime(number)) {
    console.log(number);
  }
}