最佳实践 - Collection.add（）和处理布尔返回值

Question

I did not find anything specific to this question. I have just started working with NetBeans and it thew a 'warning' about a Manual collection add loop:

for(String str : strings){ list.add(str) }

Net Beans really wanted me to handle the boolean return value from the collection addition:

for(String str : strings){ boolean add = list.add(str) }

I have never really considered if not storing/handling the return of a collection.add() method as faulty or negligent. I've seen it regularly to simply ignore the return value since it may not be valuable. Is this incorrect? What are the ramifications of not handling the return boolean value? Or is this just an IDE thing?

Thanks all.

Answer 1

The warning is not about ignoring the return value of Collection.add but instead about manually looping through an array and adding to a collection. NetBeans really does not like manual array copies and prefers you use an API method to do the copying.

In your case that would be list.addAll( Arrays.asList( strings ) ) .

Answer 2

It is the IDE warning to tell you, that the return value not used. You can close this warning in the setting.

Note: If you need to test the item was added or not in some special cases, then you can use this returned boolean value, otherwise you can ignore it.

Answer 3

put @SuppressWarnings({"unchecked", "null", "unused"}) it's funtion Eg:

@SuppressWarnings({"unchecked", "null", "unused"})
private void myfuntion() {
   ...
   for(String str : strings){ list.add(str); }

}