Java: Equivalent of Python's range(int, int)?

Solution 1:

Old question, new answer (for Java 8)

IntStream.range(0, 10).forEach(n -> System.out.println(n));

or with method references:

IntStream.range(0, 10).forEach(System.out::println);

Solution 2:

Guava also provides something similar to Python's range:

Range.closed(1, 5).asSet(DiscreteDomains.integers());

You can also implement a fairly simple iterator to do the same sort of thing using Guava's AbstractIterator:

return new AbstractIterator<Integer>() {
  int next = getStart();

  @Override protected Integer computeNext() {
    if (isBeyondEnd(next)) {
      return endOfData();
    }
    Integer result = next;
    next = next + getStep();
    return result;
  }
};

Solution 3:

I'm working on a little Java utils library called Jools, and it contains a class Range which provides the functionality you need (there's a downloadable JAR).
Constructors are either Range(int stop), Range(int start, int stop), or Range(int start, int stop, int step) (similiar to a for loop) and you can either iterate through it, which used lazy evaluation, or you can use its toList() method to explicitly get the range list.

for (int i : new Range(10)) {...} // i = 0,1,2,3,4,5,6,7,8,9

for (int i : new Range(4,10)) {...} // i = 4,5,6,7,8,9

for (int i : new Range(0,10,2)) {...} // i = 0,2,4,6,8

Range range = new Range(0,10,2);
range.toList(); // [0,2,4,6,8]

Solution 4:

Since Guava 15.0, Range.asSet() has been deprecated and is scheduled to be removed in version 16. Use the following instead:

ContiguousSet.create(Range.closed(1, 5), DiscreteDomain.integers());