Need Help - Factoring & Prime Finding Code

Hello, I'm working on a project that outputs the numbers 2 – 100.
Next to each number, it should list all the factors for that number.
If the number has no factors, it should print prime.
Ex.
2 prime
3 prime
4 2
5 prime

Having some difficulty so far. I'm aware I need to use loops, but I'm not sure what to %, and by what to determine if it's a factor.

This is my fail code so far: (I realize its horrible and is incomplete)

Code :

---

public class Prime
{
public static void main(String[] args)
 {
 	findPrime(factors());
 	factors();
 }
 public static void findPrime(int k)
  {
  	int i = 2;
  	int ans = i%k;	
 	while(i<=100)
 	{
  		System.out.println(ans);
 		i++;
  	}
 
  }
public static int factors()
  {
  	int k = 1;
  	for(k = 1; k <=100; k++)
  	{   		 	
  	}
  	return k;
  }
}

---

Any help whatsoever is greatly appreciated. Thanks!

mmm... prime numbers :(

The easiest way to do this is probably seeing if for some number 1<n<101, printing out any numbers that n%i == 0 (where i is a number from 2 to n-1). If nothing was printed out, then print out prime. You can keep track of nothing being printed out by having a boolean flag to denote the primality of the number.

Code :

---

for (int n = 2; n <= 100; n++)
{
    boolean isPrime = true; // assume n is prime
    System.out.print(n + " : ");
    for(int i = 2; i < n; i++)
     {
           if (n%i == 0)
           {
                      System.out.print(i);
                      isPrime = false;
           }
     }
     if (isPrime)
     {
          System.out.println("Prime");
     }
     else
     {
          System.out.println(""); // go to next line
}

---

Thanks alot! That helped me so much, I appreciate it, however, I need to work on the factoring part now, with that current code, it is printing some pretty strange numbers next to the non-prime numbers.
Ex.

Quote:

---

27 : 39
28 : 24714
29 : Prime
30 : 23561015
31 : Prime
32 : 24816
33 : 311
34 : 217
35 : 57
36 : 234691218
37 : Prime

---

ahh, forgot... it's not printing out any spaces between the numbers :P

Oh! haha I didn't realize those were factors! Thanks again!

lol nice one helloworld, always leave something out to confuse them. If it's solved coud you please mark it as so.

Thanks,
Chris