Method signature - ideas

Question

Look at this method signature:
public ArrayList getFollowUpEmails() throws Exception{}
This ArraysList contains several EmailTO transfer objects - but I had to tell you this. Now look at this signature:
public EmailTO[] getFollowUpEmails() throws Exception{}
See how the above method is self explaining. For classes that are to be re-used often by other developers would it be better to use arrays because they are more obvious? How do other people deal with this or do you just not worry about it and leave it up to the comments to explain?

Answer 1

See how the above method is self explaining. Yes, returning an array is more self explanatory. Are you defensively copying the array?
For classes that are to be re-used often by other developers would it be better to use arrays because they are more obvious? It depends. Yes its more obvious but if folks are going to stick the array contents into a Collection then returning a Collection is nice, too.
How do other people deal with this or do you just not worry about it and leave it up to the comments to explain?Thats what javadoc is for. i.e. @return a List of EmailTo objects
In jdk1.5 templates will help with this a bit.
One of the most painful bugs you will encounter is when you don't make defensive copies of objects and another class mutates an internal data structure. Of course, defensive copies waste object references and in some cases, can really cause a slow down. You can always provide access via ye old getNumberOfFollowUpEmails/getFollowUpEmail(int i)
Ian