How to find prime numbers between 0 - 100?

Answer 1

I have created a JSFiddle showing how it should work in a readable way,

idea is to have two functions isPrime and getPrimeNumbers to separate functionality, as well as using Math.pow and initial value of 2, as it should be always there, see the jsfiddle attached jsFiddle

window.onload = function() {
  (function() {
    var cont = document.getElementById('MainContainer');
    var curEl = document.createElement('span');
    var primeNumbers = [2];

    function fillContent() {
        var primeNumbersContent = document.createTextNode(JSON.stringify(primeNumbers));
        curEl.appendChild(primeNumbersContent);
        cont.appendChild(curEl);
    }

    function isPrime(n) {
        var divisor = 2;
        while (n > divisor) {
            if (Math.pow(divisor, 2) > n) {
                return true;
            }
            if (n % divisor == 0 || Math.sqrt(divisor) > n) {
                return false;
            } else {
                divisor++;
            }
        }
        return true;
    }

    function getPrimeNumbers(range) {
        for (var i = 3; i <= range; i+=2) {
            if (isPrime(i)) {
                primeNumbers.push(i);
            }
        }
        fillContent(primeNumbers);
    }
    getPrimeNumbers(11);
  })();
};