The withDayOfMonth() method of LocalDateTime class in Java is used to get a copy of this LocalDateTime with the dayOfMonth changed to the dayOfMonth passed as the parameter to this method. The remaining values of this LocalDateTime remains the same.
Syntax:
public LocalDateTime withDayOfMonth(int dayOfMonth)
Parameter: This method accepts a single mandatory parameter dayOfMonth which specifies the dayOfMonth to be set in the resultant LocalDateTime instance. The value of this dayOfMonth can range from 1 to 31.
Returns: The function returns a LocalDateTime instance with the dayOfMonth changed to the dayOfMonth passed as the parameter to this method. The remaining values of this LocalDateTime remains the same.
Exceptions: The function throws a DateTimeException if the dayOfMonth value is invalid.
Below programs illustrate the LocalDateTime.withDayOfMonth() method:
Program 1:
// Program to illustrate the withDayOfMonth() method import java.util.*;import java.time.*; public class GfG { public static void main(String[] args) { // Get the LocalDateTime instance LocalDateTime dt = LocalDateTime.now(); // Get the String representation of this LocalDateTime System.out.println("Original LocalDateTime: " + dt.toString()); // Get a new LocalDateTime with dayOfMonth 25 System.out.println("New LocalDateTime: " + dt.withDayOfMonth(25)); }} |
Original LocalDateTime: 2018-11-30T10:38:27.429 New LocalDateTime: 2018-11-25T10:38:27.429
Program 2:
// Program to illustrate the withDayOfMonth() method import java.util.*;import java.time.*; public class GfG { public static void main(String[] args) { // Get the LocalDateTime instance LocalDateTime dt = LocalDateTime .parse("2015-04-06T10:15:30"); // Get the String representation of this LocalDateTime System.out.println("Original LocalDateTime: " + dt.toString()); // Get a new LocalDateTime with dayOfMonth 1 System.out.println("New LocalDateTime: " + dt.withDayOfMonth(1)); }} |
Original LocalDateTime: 2015-04-06T10:15:30 New LocalDateTime: 2015-04-01T10:15:30
Reference: https://docs.oracle.com/javase/10/docs/api/java/time/LocalDateTime.html#withDayOfMonth(int)