Thread: bubble sorting

can anyone help me ? i have an assignment about sorting alphabetically. i tried to search information on google, i found the codes, but i just cant understand. heres what i dont understand. please help

public class Alphasortingbubble
{
     public static void main(String[ ] args)
     {
             String[ ] names = {"joe", "slim", "ed", "george"};
             sortStringBubble (names);
             for ( int k = 0;  k < 4;  k++ )
                System.out.println( names [ k ] );
      }
 
      public static void sortStringBubble( String  names [ ] )
      {
            boolean flag = true;  // will determine when the sort is finished
            String temp;
 
            while ( flag )
            {
                  flag = false; // i dont understand why this is false
                  for (int i = 0;  i < names.length - 1;  i++ )
                  {
                          if ( names [ i ].compareTo( names [ i+1 ] ) > 0 )
                          {
							  // ascending sort
 
							/*i print this one and the result is number. i dont understand where the numbers come from
							  System.out.println( "nama : " + names [ i ].compareTo( names [ i+1 ] )); */
 
                                      temp = names [ i ];
                                      names [ i ] = names [ i+1];     // swapping
                                      names [ i+1] = temp;
                                      flag = true; //why this is true
                           }
                   }
            }
      }
}