Comments on: Bad and Good (code snippets)

By: Rob Church

Rob Church — Thu, 30 Dec 2010 23:03:51 +0000

Syntactically correct:

public ArrayList getSomething() {}

Better:

public List getSomething() {}

Even better:

public List 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.)

By: cherouvim

cherouvim — Tue, 10 Feb 2009 17:36:15 +0000

@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.

By: shaun

shaun — Tue, 10 Feb 2009 17:02:36 +0000

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

By: cherouvim

cherouvim — Tue, 08 Jul 2008 13:30:35 +0000

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.

By: Ioannis Mavroukakis

Ioannis Mavroukakis — Tue, 08 Jul 2008 13:22:42 +0000

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.

By: dik_

dik_ — Thu, 21 Feb 2008 15:41:02 +0000

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 ;)

By: John Kostaras

John Kostaras — Wed, 19 Dec 2007 15:20:25 +0000

http://findbugs.sourceforge.net/

By: papo

papo — Mon, 27 Aug 2007 10:53:48 +0000

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!

By: John Kostaras

John Kostaras — Wed, 22 Aug 2007 09:01:35 +0000

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

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

By: John Kostaras

John Kostaras — Tue, 21 Aug 2007 08:14:10 +0000

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…