Java: is there a map function?

java map-function
Albert picture Albert · Oct 11, 2010 · Viewed 123.2k times · Source

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

leventov picture leventov · Jan 8, 2014

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

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

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

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