public void score()
    {
   int correct = 0;
   int incorrect = 0;
    int[] n1 = {-3,-2,-1} ;
    if( absVals(n1 )[0] == 3 && absVals(n1)[1] == 2 &&  absVals(n1 )[2] == 1)
        correct++ ;
    else
        {
        print("absVals({-3,-2,-1})  incorrect");
        incorrect++;
        }

    int[] n2 = {9,10,11} ;
    String[] str1 = {"x", "y", "z"} ;
    if( concat(str1,n2)[0].equals("x9") &&  concat(str1,n2)[1].equals("y10") &&  concat(str1,n2)[2].equals("z11")  )
        correct++ ;
    else
        {
        print("concat({x,y,z}, {9,10,11}  }) incorrect");
        incorrect++;
        }

   if( longer("ab","abc").equals("abc"))
        correct++ ;
    else
        {
        print("longer(ab,abc) incorrect");
        incorrect++;
        }
    if( toArr("abc")[0].equals("a") && toArr("abc")[1].equals("b") && toArr("abc")[2].equals("c")      )
        correct++ ;
    else
        {
        print("toArr(bc) incorrect");
        incorrect++;
        }
    if( toArr("ab")[0].equals("a") && toArr("abc")[1].equals("b")       )
        correct++ ;
    else
        {
        print("toArr(ab) incorrect");
        incorrect++;
        }
    if( toArr("a")[0].equals("a")       )
        correct++ ;
    else
        {
        print("toArr(a) incorrect");
        incorrect++;
        }

    //
    print("total correct :" + correct);
    print("total incorrect :" + incorrect);

    }

void print(String s){
        System.out.println(s);
    }