Java: is there a map function?

Question

I need a map function. Is there something like this in Java already?

(For those who wonder: I of course know how to implement this trivial function myself...)

Answer 1

Since Java 8, there are some standard options to do this in JDK:

Collection in = ...
Object[] mapped = in.stream().map(e -> doMap(e)).toArray();
// or
List mapped = in.stream().map(e -> doMap(e)).collect(Collectors.toList());

See java.util.Collection.stream() and java.util.stream.Collectors.toList().