Question

I know it is a primitive question but I want to learn the smartest way.

I want to loop over the ArrayList<Integer> intList and it can be null. I have 2 ways of doing it

if(intList != null) {
     for(int i = 0; i < intList.size(); i++){
             System.out.println(intList.get(i));
     }
}

and

for (int i = 0; intList != null && i < intList.size(); i++){
     System.out.println(intList.get(i));
}

First way seems more pretty to me. What do you think? What are your implementations in that situation?

Excuse me, if it is duplicate question but I can’t find one

Thanks

Answer 1

In this case I would choose the first implementation as well because its intent is clearer.

Generally, I would try to avoid a List (or any other Collection object, really) being null. When evaluating a List (which is suddenly and unexpectedly null) you most probably want to abort before any processing takes place so either case of looping over the collection would not occur.