ioannis cherouvim

if (foo>bar) {
  return true;
} else {
  return false;
}

return foo>bar;

if (foo) {
  if (bar) {
    // do something
  }
}

if (foo && bar) {
  // do something
}

if (foo!=null && foo.equals("bar")) {
  // do something
}

if ("bar".equals(foo)) {
  // do something
}

String comment = request.getParameter("post");
if (comment==null) {
  comment = "n/a";
}

String comment = request.getParameter("post")!=null?
        request.getParameter("post"):
        "n/a";

Something something = new Something(foo);
return something;

return new Something(foo);

Something something = new Something();
if (foo) {
  something.prepare();
  request.setAttribute("something", something);
}

if (foo) {
  Something something = new Something();
  something.prepare();
  request.setAttribute("something", something);
}

public ArrayList getSomething() {
  ...
}

public List getSomething() {
  ...
}

String foo = "something";
if (!foo.equals("")) {
  // do something
}

String foo = "something";
if (foo.length()>0) {
  // do something
}

List immutableList = new ArrayList();
immutableList.add(foo);
immutableList.add(bar);
immutableList.add(example);
Something something = new Something(immutableList);

Something something = new Something(
        Arrays.asList(new Object[] {foo, bar, example}));

10 Responses to “Bad and Good (code snippets)”

1. John Kostaras Says:
   August 21st, 2007 at 10:14

   Πολύ ωραία τα παραπάνω και πολύ χρήσιμα που τα μάζεψες εδώ. Επίσης χρήσιμο είναι και όταν ξέρεις ότι μια μεταβλητή η παράμετρος δεν αλλάζει να την ορίζεις final. Καλή συνέχεια…

2. John Kostaras Says:
   August 22nd, 2007 at 11:01

   And don´t use try-catch to make decisions; use if:

   http://www.sdnshare.com/view.jsp?id=781

3. papo Says:
   August 27th, 2007 at 12:53

   ωραίο post …παρόλα ομολογώψ ότι συνειδητά το

   πρώτο πρώτο και το άλλο με το return new()-

   βασικά αποφεύγω ιδιαίτερα σε pre-mature implementation την χρήση inline calls σε return statements! από δικη μου εμπειρία καθώς ο κώδικας εξελίσσεται τέτοια inline statements με γ@μ@νε!

4. John Kostaras Says:
   December 19th, 2007 at 17:20

   http://findbugs.sourceforge.net/

5. dik_ Says:
   February 21st, 2008 at 17:41

   Nice snippets :)

   Regarding the “Too much variable scope” one, may I add that a new Something instance will be created even if foo is false, taking up unnecessarily memory. So there’s another reason to move the instantiation in the if block ;)

6. Ioannis Mavroukakis Says:
   July 8th, 2008 at 16:22

   Ah the age old chestnut of readability versus one liners..for me

   String comment = request.getParameter(“post”);
   if (comment==null) {
   comment = “n/a”;
   }

   Is much more readable and I am willing to loose the ill perceived coolness of ternary expressions.

7. cherouvim Says:
   July 8th, 2008 at 16:30

   Ioanni thanks for your comment.

   If it helps you then good for you.
   I don’t think that using the ternary operator is a matter of coolness though.

8. shaun Says:
   February 10th, 2009 at 20:02

   A noob programmer here so forgive me if I’m asking a stupid question. Regarding “Method exposes implementation”, shouldn’t it be better to return an ArrayList instead of a List? Therefore the caller (expecting an ArrayList) does not have to cast the returned value. No?

   Great site btw

9. cherouvim Says:
   February 10th, 2009 at 20:36

   @shaun: Good question.
   The interface List contains everything that a user of a List implementation would like to do, such as add(), remove(), indexOf() etc. The point is that it shouldn’t matter what the underlying implementation of List is (ArrayList? LinkedList? Vector? etc). So the client shouldn’t need to downcast anyway.

10. Rob Church Says:
    December 31st, 2010 at 2:03

    Syntactically correct:

    public ArrayList getSomething() {}

    Better:

    public List getSomething() {}

    Even better:

    public List<T> getSomething() {}

    (Assuming that getSomething() is able to return a type-safe generic list, and isn’t in fact returning a collection of arbitrary types, in which case you’ve got other problems anyway. Also assumes you can use generics, and thus implies JDK 1.5, and if you can’t, my sympathies.)