Prime numbers

by Abhishek Kumar

HTML

<input type=text id=num>
<button onclick="checkPrime()">
	Is Prime?
</button>
<div id=result></div>

JavaScript

/* function isPrime(n) {
	if (n <= 1) {
		return false;
	}
	if (n in [2,3,5,7]) {
		return true;
	}
  if (n % 2 == 0 || n % 3 == 0 || n % 5 == 0 || n % 7 == 0) {
    return false;
  }
  return true;
} */

function isPrime(n) {
  if (n <= 1) {
    return false;
  }
  for (let i = 2; i <= Math.sqrt(n); i++) {
    if (n % i === 0) {
      return false;
    }
  }
  return true;
}

function checkPrime() {
	let num = document.getElementById('num').value;
	let result = isPrime(num);
	console.log(result);
	document.getElementById('result').textContent = result;
}