Re: Adding Contents of a Vector

From:

Patricia Shanahan <pats@acm.org>

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 08 Sep 2006 16:57:49 GMT

Message-ID:

<hihMg.8696$bM.7513@newsread4.news.pas.earthlink.net>

Vera wrote:

This is what I have:
--------------------------------------------------------------------
         Vector tokens = new Vector();

         try
         {
             // Start reading the file
             FileReader fr = new FileReader(file);
             BufferedReader inFile = new BufferedReader(fr);

             // Read the file till EOF
             while((line = inFile.readLine())!= null)
            {
              tokenizer = new StringTokenizer(line);

                    // Convert string to double format
                    Double lineD = Double.parseDouble(line);

           // Print number
           // System.out.println(lineD);

            // Store number in array
            tokens.add(lineD);
             }
----------------------------------------------------------------------------------

tokens contains references to Double objects.

There are two paths from here to where you want to be. I'm going to
discuss the older path, rather than opening the generic and autoboxing
cans of worms.

The result of tokens.elementAt(count) is an expression of type Object,
referring to a Double object. You need to do two things to make it
something you can add, change the expression type from Object to Double
with a cast, and invoke a Double method to get the double value:

sum += ((Double)tokens.elementAt(count)).doubleValue();

Patricia