Is it possible to pass an array by value?

Question

I am trying to create a list of String arrays holding all the different possible combinations for a little problem I was working on. the function Solve takes a String array argument that is passed by reference and so when I add a value to it all of the previous String array values for str get that value when I want each of them to have their own values. Can I pass the string array by value? or do I just need to change my code....and if it is the latter, any tips on structuring my code?
Thanks
import java.util.ArrayList;
public class Solution
     Solution()
     public ArrayList<String[]> solve = new ArrayList<String[]>();
     public String[] Direction = {"LEFT","RIGHT","TOP","BOTTOM","C_LEFT","C_RIGHT","C_TOP","C_BOTTOM","FSLASH","BSLASH"};
     public boolean isNextTo(String a, String b)
          return true;
     public boolean notUsed(String[] s, String a)
          for(int i=0;i<s.length;i++)
               if(s[i] == a)
                    return false;
          return true;
     public String[] Solve(String[] str, int element)
          //solve.add(str);
          int index = solve.size()-1;
          for(int dir=0;dir<10;dir++)
               System.out.println("\nchecking " + Direction[dir] + " for element " + element);
               printList();
               //if(isNextTo(str[element], Direction[dir]));
                    if(notUsed(str, Direction[dir]))
                         System.out.println("\nadding " + Direction[dir] + " to the list ");
                         str[element+1] = Direction[dir];
                         solve.add(Solve(str,element+1));
          return str;          
     public void printList()
          for(int i=0;i<solve.size();i++)
               System.out.println("\nSolution " + i + ":");
               for(int j=0;j<10;j++)
                    System.out.print(solve.get(i)[j] + ", ");
     public static void main(String args[])
          Solution s = new Solution();
          String[] a = new String[10];
          a[0] = "LEFT";
          s.solve.add(a);
          s.Solve(a, 0);
          s.printList();
}Edited by: newms86 on May 19, 2008 2:10 AM

Answer 1

I tried adding in a clone array like this:
public String[] Solve(String[] str, int element)
          //solve.add(str);
          String[] a = str;
          for(int dir=0;dir<10;dir++)
               System.out.println("\nchecking " + Direction[dir] + " for element " + element);
               printList();
               if(isNextTo(str[element], Direction[dir]));
                    if(notUsed(str, Direction[dir]))
                         System.out.println("\nadding " + Direction[dir] + " to the list ");
                         a[element+1] = Direction[dir];
                         solve.add(Solve(a,element+1));
          return str;          
     }but all the elements in the ArrayList are the same. What do I need to change?
Edited by: newms86 on May 19, 2008 2:23 AM