Thread: Modulus with BigIntegers

Hey, so I'm trying to make a method that checks if a BigInteger is prime, but I'm running into an issue in doing the modulus. Below is the whole method.

public static boolean isPrimeItself(BigInteger input)
{
boolean answer = true;
BigInteger zero = new BigInteger(""+0+"");
for(int i=2;i<100/*I wasn't sure what to make this because I want it to be input but input is a BigInt...*/;i++) {
BigInteger temp = new BigInteger(""+i+"");
System.out.println(temp);
if (temp.remainder(input)==zero)
{
answer = false;
System.out.println("Success!");
}
}
return answer;
}

I included the print lines to see where it was going wrong, and the if test [if (temp.remainder(input)==zero)] is never being activated. Did I make a mistake in using the remainder method? Upon researching I know there seems to be a premade method that does this, but I'm really just trying to practice using BigIntegers. Thanks for any comments / help you can provide!

Got it! Silly mistake. I should have used compareTo instead of ==. My current issue is that I need to use BigIntegers in the conditions of the for loop, is that not allowed? Because my method seems to get stuck in a loop when I try it.