Hi, I've got a method that returns 'null' for a linked list
public LinkedList<names> Relate(names Student) {
return null;
How can i get it to return an empty List, so that I dont get a null pointer exception?
Thanks in advance,
Hi, I've got a method that returns 'null' for a linked list
public LinkedList<names> Relate(names Student) {
return null;
How can i get it to return an empty List, so that I dont get a null pointer exception?
Thanks in advance,
null value represents the empty list
if(Relate(names Student) == null)
//empty list
else
//not empty
Well, turingmachine completely ignored the question.
Just return an empty list
return new LinkedList<names>();
or you could also define an empty list class constant to use for that purpose
public final static LinkedList<names> EMPTY_LIST = new LinkedList<names>();
A couple of additional thoughts:
- Do you really need to return a LinkedList? It's usually better to use the interface List, so as not to nail yourself to using a particular list class.
- Why is "names" lowercase? Class names should begin with a capital.
- The EMPTY_LIST should probably be unmodifiable unless you explicitly expect callers to add data to that list, which is probably not a good idea anyway
public final static List<names> EMPTY_LIST = Collections.unmodifiableList(new LinkedList<names>());
I'm so sorry.
I misunderstood the question.
Ezzaral was right.
For the simplest way, you can just put/add this to the method:
return new LinkedList<names>();
please disregard my previous reply.
null can equate to an empty list but it represents more to a non-existing list/"value" :)
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