Prime factor and JavaScript

Question

I\'m stuck with the JavaScript code I am using for solving a problem which states:

The prime factors of 13195 are 5, 7, 13 and 29. What is the largest p

Answer 1

My javascript solution-

<script type="text/javascript">
function largestPrimeFactor(number) {
var i = 2;
while (i <= number) {
    if (number % i == 0) {
        number /= i;    
    } else {
        i++;
    }
}
console.log(i);
}
var a = 600851475143 ; 
largestPrimeFactor(a)
</script>

Answer 2

Your issue isn't a mathematical one -- you just have a bug in one of your conditional checks.

Change if(b = n-1) to if(b == n-1). Right now, your code isn't actually checking to ensure that a factor is prime; instead, it's assigning the value of n-1 to b (for odd values of n) and then automatically calling a1(b), so your result is all possible odd factors of k.