LocalDateTime withNano() method in Java

An immutable copy of a LocalDateTime with the nanoseconds altered as required is done using the method withNano() in the LocalDateTime class in Java. This method requires a single parameter i.e. the nanosecond that is to be set in the LocalDateTime and it returns the LocalDateTime with the nanosecond altered as required.

A program that demonstrates this is given as follows −

Example

 Live Demo

import java.time.*;
public class Main {
   public static void main(String[] args) {
      LocalDateTime ldt1 = LocalDateTime.parse("2019-02-18T23:15:30");
      System.out.println("The LocalDateTime is: " + ldt1);
      LocalDateTime ldt2 = ldt1.withNano(5);
      System.out.println("The LocalDateTime with nanosecond altered is: " + ldt2);
   }
}

Output

The LocalDateTime is: 2019-02-18T23:15:30
The LocalDateTime with nanosecond altered is: 2019-02-18T23:15:30.000000005

Now let us understand the above program.

First the LocalDateTime is displayed. Then the LocalDateTime with the nanosecond altered to 5 is displayed using the method withNano(). A code snippet that demonstrates this is as follows −

LocalDateTime ldt1 = LocalDateTime.parse("2019-02-18T23:15:30");
System.out.println("The LocalDateTime is: " + ldt1);
LocalDateTime ldt2 = ldt1.withNano(5);
System.out.println("The LocalDateTime with nanosecond altered is: " + ldt2);