Functions and Function Expressions - task-2

/* Task description */
/*
	Write a function that finds all the prime numbers in a range
		1) it should return the prime numbers in an array
		2) it must throw an Error if any on the range params is not convertible to `Number`
		3) it must throw an Error if any of the range params is missing
*/

function findPrimes(from, to) {
	if (isNaN(Number(from)) || isNaN(Number(to))) {
		throw new Error('At least one param is not convertible to `Number` or not passed');
	}

	var primesArr = [];

	// Exchange range values if nessesary for while loop condition
	if (from > to) {
		from = from + to;
		to = from - to;
		from = from - to;
	}

	while(from <= to){
		var prime = isPrime(from);

		if (prime) {
			primesArr.push(prime);
		}

		from += 1;
	}

	return primesArr;
}


function isPrime(num){
	if (num <= 1) {
		return false;
	}else if (num === 2) {
		return num;
	}

	var i,
		numSquareRoot = Math.ceil(Math.sqrt(num));

	for (i = 2; i <= numSquareRoot; i++) {
		if (num % i === 0) {
			return false;
		}
	}

	return num;
}