primenumbers_java's Introduction

PrimeNumbers_Java

I made this today to pass the time. Source copied below for convenience, old technique redacted for space.

package primeNumbers;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
 * @author drewry pope
 */
public class Main {
  //New method, divide iO against every found prime up to iO
  public static void main(String[] args)
  {
    List<Integer> primeNumbers= new ArrayList<Integer>(); //initialize new ArrayList to store primes
    for (int iO = 2; iO <= 100; iO++) { //For numbers 2 to 100
      for (int iI = 0; iI <= primeNumbers.size(); iI++) { //For primeNumbers index 0 to end of List
        if (iI == primeNumbers.size()) { //if on last iteration, 
          primeNumbers.add(iO); //then add iO as prime
        }else if (0 != iO % primeNumbers.get(iI)) { //if iO is not divisible by primeNumber(iI)
          continue; //then continue from beginning of inner for loop
        }
        break; //exit inner For loop if number divides by primeNumber(iI) or number was added as prime
      } 
    }
    Iterator<Integer> itr = primeNumbers.iterator();  //initialize an iterator to output array
    System.out.print(itr.next()); //print first prime without a comma
    while(itr.hasNext()) { //while there's still more integers to iterate
           System.out.print(", " + itr.next()); //print next number with minor formatting
      }
  }
}

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