Can someone explain me this program based on nested loops?

[Raghuram99]

#include <iostream>
using namespace std;
 
int main ()
{
   int i, j;
   
   for(i=2; i<100; i++) 
   {
      for(j=2; j <= (i/j); j++)
        if(!(i%j)) break; // if factor found, not prime
        if(j > (i/j)) cout << i << " is prime\n";
   }
   return 0;
}

I want to know the logic and how to flow of control processes the program.

[koothkeeper]

This code is very poorly formatted.

First of all, please post your code using the code tags under the Format: area.

So, something like this:

#include <iostream>
using namespace std;

int main ()
    {
    int
        i = 0,
        j = 0;    //    Get in the habit of initializing all variables!

    for( i = 2;  i < 100;  i++ ) 
        {
        for( j = 2;  j <= ( i / j );  j++ )
            {
            if( ! ( i % j ) )
                break;        // if factor found, not prime

            }    /*   The second "for" loop    */

        if( j > ( i / j ) )
            cout << i << " is prime\n";

        }    /*    The first "for" loop    */

    return 0;

    }
        /*    main()    */

This should be easier to read. Now if you can't figure it out, please come back and ask your questions again.