What is an easy way to convert a String[] to a Collection<Integer>? This is how I'm doing it right now but not sure if it's good:
String[] myStringNumbers;
Arrays.stream(Arrays.asList(myStringNumbers).stream().mapToInt(Integer::parseInt).toArray()).boxed().collect(
Collectors.toList());
You don't need to make an intermediate array. Just parse and collect (with static import of Collectors.toList):
Arrays.stream(myStringNumbers).map(Integer::parseInt).collect(toList());
It is unnecessary to use parseInt as it will box the result to the collection, and as @Misha stated you can use Arrays.stream to create the stream. So you can use the following:
Arrays.stream(myStringNumbers).map(Integer::decode).collect(Collectors.toList());
Please note that this does not do any error handling (and the numbers should not start with 0, # or 0x in case you do not want surprises). If you want just base 10 numbers, Integer::valueOf is a better choice.
int values are boxed in either case, so whether you use valueOf or parseInt makes no difference. And it’s quite strange to recommend the use of a different method like decode followed by a warning about the surprises caused by the fact that this method has a different purpose.Here is what I think:
String[] myStringNumbers = {"1", "2"};
List<Integer> list = Stream.of(myStringNumbers).map(Integer::valueOf).collect(Collectors.toList());
I hope it can be some help. :)
