The naturalOrder() method of Comparator Interface in Java returns a comparator that use to compare Comparable objects in natural order. The returned comparator by this method is serializable and throws NullPointerException when comparing null.
Syntax:
static <T extends Comparable<T>> Comparator<T> naturalOrder()
Parameters: This method accepts nothing.
Return value: This method returns a comparator that imposes the natural ordering on Comparable objects.
Below programs illustrate naturalOrder() method:
Program 1:
// Java program to demonstrate // Comparator.naturalOrder() method import java.util.Arrays; import java.util.Comparator; import java.util.List; public class GFG { public static void main(String... args) { List<Integer> values = Arrays.asList( 212 , 324 , 435 , 566 , 133 , 100 , 121 ); // naturalOrder is a static method values.sort(Comparator.naturalOrder()); // print sorted number based on natural order System.out.println(values); } } |
The output printed on console of IDE is shown below.
Output:
Program 2:
// Java program to demonstrate // Comparator.naturalOrder() method import java.util.Arrays; import java.util.Comparator; import java.util.List; public class GFG { public static void main(String... args) { List<String> stringList = Arrays.asList( "Aman" , "Kajal" , "Joyita" , "Das" ); System.out.println( "Before sorting:" ); stringList.forEach(System.out::println); stringList.sort(Comparator.naturalOrder()); System.out.println( "\nAfter sorting:" ); stringList.forEach(System.out::println); } } |
The output printed on console is shown below.
Output:
References: https://docs.oracle.com/javase/10/docs/api/java/util/Comparator.html#naturalOrder()