CODEWITHSUNDEEP
javaarraylistnullpointerexception
cshadowstar
cshadowstar

Reputation: 303

How to get size() of initialized ArrayList?

I have some code similar to this:

ArrayList<SomeType> toGetSizeOf = new ArrayList<SomeType>();
int size = toGetSizeOf.size();

However, the second line is giving me a NullPointerException. Is there some way to avoid this, to basically tell if the ArrayList has been initialized but has not as of yet had anything added to it yet? (I have an if/else statement dependent on this).

Thanks in advance!

Upvotes: 0

Views: 570

Answers (2)

athor
athor

Reputation: 6928

I think perhaps something else is wrong in your code.

The following works fine:

ArrayList<String> toGetSizeOf = new ArrayList<String>();
int size = toGetSizeOf.size();
System.out.println(size);

Which gives 0.

Debug your code and check what is actually null. I suspect it's your toGetSizeOf.

Upvotes: 2

MadProgrammer
MadProgrammer

Reputation: 347332

If you having issues with a NullPointerException then you should be checking for it first

You could use...

int size = 0;
if (toGetSizeOf != null) {
    size = toGetSizeOf.size();
}

or...

int size = toGetSizeOf == null ? 0 : toGetSizeOf.size();

You could also use ArrayList#isEmpty which returns a boolean true, if the list is empty (size == 0) or false if it is not, depending on your needs

Upvotes: 0

Related Questions