Question

In PS2 I'm having problem with test method for primes... How to solve that?

Answer 1

I'm not sure what class you are taking, but I would imagine from a pseudocode perspective the best approach to finding out if a number is a prime is to use an incremental loop which divide the number by the loop counter and sees if there is a remainder. If there is no remainder then the number is not a prime. You will ant to skip the number 1 and the number itself so the loop will go from 2 to n-1.

prime = true;
for (i=2; i < (n-1); i++)
{
if ((n % i)=0)
{
prime = false;
}
}

Nothing fancy but a basic Java loop to address the question.

Answer 2

Post your code, ask a specific question and we'll have something to help you with. Otherwise, the answer to your question is: consider the attributes that make a number prime, and develop tests for each of those characteristics.