It's been a while since I last used Java, so forgive me if the question is stupid. In Ruby, I use .map quite a lot. Is there something similar in Java or do I have to iterate over the Array?
In Ruby, instead of
output = []
input.each do |elem|
output << SomeClass.new(elem)
end
I can write
output = input.map { |elem| SomeClass.new(elem) }
Yes, with Java 8 you can use streams to iterate over collections implicitly. For example:
final List<String> strings = Arrays.asList("Me", "You");
final List<String> reducedStrings = strings.stream().map(s -> s.substring(1)).collect(Collectors.toList()); // [ "e", "ou" ]
Reference: https://docs.oracle.com/javase/8/docs/api/java/util/stream/Collectors.html#toList--
Since Java 8 and its support for lambda expressions and its stream API:
List<SomeClass> result = someCollection.stream()
.map(SomeClass::new)
.collect(Collectors.toList());
If you're really using an array and not a collection (you should prefer collections almost always), then you can create a strem over the array using
Arrays.stream(array)
