Python Example

gistfile1.txt

Python:

# Even numbers between 1 and 49:
[ x for x in range(1,50) if x % 2 == 0 ]

Java:

// Even numbers between 1 and 49:
IntStream.range(1, 50).filter(x -> x % 2 == 0).boxed().collect(toList());

Comprehension with java 8 and groovy-streams ;-)

import groovy.stream.Stream;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Comprehend {
    public static void main(String[] args) {
        Map<String,List<Integer>> map = new HashMap<String,List<Integer>>() {{
            put( "x", Arrays.asList( 1, 2, 3 ) ) ;
            put( "y", Arrays.asList( 4, 5, 6 ) ) ;
        }} ;
        Stream.from(map)
              .map(entry -> entry.get("x") + entry.get("y"))
              .forEachRemaining(System.out::println);
    }
}