The product of all integers in an array

[James Allen A.]

I suppose my question is broader than for just integers, but I really mean for all numbers in the ArrayList. Is there a method for returning the product for all numbers within the ArrayList? If my ArrayList values are [2, 5, 10] I would like it to return 100. I'm not sure it will solve the road block I've hit in my program but I want to give it a crack.

[Ivan Jozsef Balazs]

What about writing it?

A sidenote: think about the appropriate return data type. Multiplication can lead fast to integer overflow.

[Ivan Jozsef Balazs]

13 factorial does not fit into an int.

2 2 2
3 6 6
4 24 24
5 120 120
6 720 720
7 5040 5040
8 40320 40320
9 362880 362880
10 3628800 3628800
11 39916800 39916800
12 479001600 479001600
13 1932053504 6227020800

public class q
{
  public static void main( String args[] )
  {
    int         si = 1;
    long        li = 1;

    for ( int i = 2; ; i++ )
    {
      si *= i;
      li *= i;
      System.out.printf( "%5d %10d %10d%n", i, si, li );
      if ( si != li )
      {
        break;
      }
    }
  }
}

[James Allen A.]

Just felt like I had my hands full enough with the rest of the code. I suppose I could give it a shot. Maybe integers aren't the best choice. I'm writing a coin calculation program and hadn't considered that the user would enter a large number for a coin but I suppose I should account for that.