Re: The greeting code in Java

From:

Stanimir Stamenkov <s7an10@netscape.net>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 19 Jun 2011 19:07:10 +0300

Message-ID:

<itl6rc$qq1$1@dont-email.me>

Sun, 19 Jun 2011 06:06:17 -0700 (PDT), /Saeed Amrollahi/:

     public static void main(String[] args) throws IOException {
         System.out.print("Please enter your first name: ");
         String name = new String();
         Reader r = new InputStreamReader(System.in);
         for (char ch; (ch = (char)(r.read())) != '\n'; name += ch) {}
         System.out.println("Hello, " + name);
     }

What are the problems of my code and how can I write
a better one. Please throw some light.

You don't need to initialize 'name' with a 'new String()' - just
assign it with an empty string literal which is a constant:

         String name = "";

The 'name += ch' will assign it a new String instance, also. In
this regard you may better use a StringBuilder:

         StringBuilder name = new StringBuilder();
         Reader r = new InputStreamReader(System.in);
         int ch = r.read();
         while (ch != -1 && ch != '\n') {
             name.append((char) ch);
             ch = r.read();
         }
         System.out.println("Hello, " + name);

In the above snippet I also check whether the Reader is returning
-1, which would mean 'System.in' has been closed for some reason -
otherwise you risk going in infinite loop, in that case.

--
Stanimir