Java Date - compareTo() Method

The java.util.Date.compareTo() method is used to compare two Dates for ordering. The method returns a value 0 if the argument Date is equal to this Date; a value less than 0 if this Date is before the Date argument; and a value greater than 0 if this Date is after the Date argument.

Syntax

public int compareTo(Date anotherDate)

Parameters

Return Value

Returns the value 0 if the argument Date is equal to this Date; a value less than 0 if this Date is before the Date argument; and a value greater than 0 if this Date is after the Date argument.

Exception

Throws NullPointerException, if anotherDate is null.

Example:

In the example below, the java.util.Date.compareTo() method is used to compare given Dates.

import java.util.*;

public class MyClass {
  public static void main(String[] args) {
    //creating Dates
    Date Dt1 = new Date();
    Date Dt2 = new Date(1000);
    Date Dt3 = new Date(2000);

    //comparing Dt1 with Dt2
    System.out.println("Comparing Dt1 with Dt2: " + Dt1.compareTo(Dt2));

    //comparing Dt1 with Dt3
    System.out.println("Comparing Dt1 with Dt3: " + Dt1.compareTo(Dt3));

    //comparing Dt1 with Dt1
    System.out.println("Comparing Dt1 with itself: " + Dt1.compareTo(Dt1));
  }
}

The output of the above code will be:

Comparing Dt1 with Dt2: -1
Comparing Dt1 with Dt3: 1
Comparing Dt1 with itself: 0