In response to https://stackoverflow.com/questions/45528735/reusing-the-same-value-inside-of-a-java-stream

EquationStream.java

public class EquationStream {

	public static void main(String[] args) {
		List<Month> months = new ArrayList<>(12);

		months.add(new Month(1, "January"));
		months.add(new Month(2, "February"));
		months.add(new Month(3, "March"));
		months.add(new Month(4, "April"));
		months.add(new Month(5, "May"));
		months.add(new Month(6, "June"));
		months.add(new Month(7, "July"));
		months.add(new Month(8, "August"));
		months.add(new Month(9, "September"));
		months.add(new Month(10, "October"));
		months.add(new Month(11, "November"));
		months.add(new Month(12, "December"));

		int[] res = months.stream()
				.map(month -> new Pair(month.number, month.number * 2))
				.map(pair -> new Pair(pair.x, pair.y + 10))
				.map(pair -> new Pair(pair.x, pair.y / 2))
				.map(pair -> new Pair(pair.x, pair.y - pair.x))
				.mapToInt(pair -> pair.y)
				.toArray();

		System.out.println("Result is " + Arrays.toString(res));
	}


	private static class Month {

		int number;
		String name;

		public Month(int month, String name) {

			this.number = month;
			this.name = name;

		}
	}

	private static class Pair {
		int x;
		int y;

		public Pair(int x, int y) {
			this.x = x;
			this.y = y;
		}
	}
}