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Ohhhh, non-prime numbers also would have that factor.

Have a for loop that starts at 3


public static boolean isPrime(int num)
{

if (num <=1)
return false;

if(num%1==0 && num%num==0)

num%1 means the remainder of num/1 which is 0.

num/num = 1 with remainder 0.

Always true unless perhaps num = 0;