How to sort and reverse a double list elements?

There are multiple way to sort and reverse a double list elements.

Using java 8 sorted() and Comparator.reverseOrder() method :-

  • First convert Arrays to list using Arrays.asList method.
  • Now, get Stream data from List using arrayList.stream() method.
  • Here Stream sorted() method returns a stream of the elements according to natural order.
  • Comparator.reverseOrder() method returns a comparator that reverse of natural order elements using Comparable objects.
  • Now printing the descending sorted list elements.

Using java 7 sort() and Collections.reverseOrder() method :-

  • Using sort() method of Collections class to sort the elements and passing list.
  • Using Collections.reverseOrder() method to sort the elements in descending order.
  • Now printing the descending sorted list elements.

        syntax :-  Collections.sort(decimalList, Collections.reverseOrder()); 

				
					import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;

public class Test {
	public static void main(String[] args) {

		// Using java 8 sorted() and Comparator.reverseOrder() method
		List<Double> decimalList = Arrays.asList(11.45, 23.87, 17.54, 32.89, 98.78, 21.34, 56.54, 121.78);
		// System.out.println("using java 8:- ");
		List<Double> dList = decimalList.stream().sorted().sorted(Comparator.reverseOrder())
				.collect(Collectors.toList());
		System.out.println("Using java 8 :- " + dList);

		// Using java 7 sort() and Collections.reverseOrder() method
		Collections.sort(decimalList, Collections.reverseOrder());
		System.out.println("Using java 7 :- " + decimalList);
		}
	}

Output :-
Using java 8 :- [121.78, 98.78, 56.54, 32.89, 23.87, 21.34, 17.54, 11.45]
Using java 7 :- [121.78, 98.78, 56.54, 32.89, 23.87, 21.34, 17.54, 11.45]