LocalTime compareTo() method in Java with Examples

The compareTo() method of a LocalTime class is used to compare this LocalTime object to the LocalTime passed as parameter to check whether both LocalTimes are equal. The comparison between both LocalTimes is based on timeline position of the local times within a day. The value to be returned by this method is determined as follows:

• if this LocalTime is greater than LocalTime passed as a parameter, then a positive value is returned
• if this LocalTime is equal to the LocalTime passed as a parameter, then a zero (0) is returned
• if this LocalTime is less than LocalTime passed as a parameter then a negative value is returned.

Syntax:

public int compareTo(LocalTime other)

Parameters: This method accepts a single parameter LocalTime which is the other LocalTime to be compared, and it should not be null.

Return Value: This method returns the int value and returned value is determined as follows:

• if this LocalTime is greater than LocalTime passed as a parameter, then a positive value is returned
• if this LocalTime is equal to the LocalTime passed as a parameter, then a zero (0) is returned
• if this LocalTime is less than LocalTime passed as a parameter then a negative value is returned.

Below programs illustrate the compareTo() method:

Program 1: When this LocalTime is greater

// Java program to demonstrate
// LocalTime.compareTo() method

import java.time.*;

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

        // create a LocalTime Objects
        LocalTime time1
            = LocalTime.parse("17:52:49");
        LocalTime time2
            = LocalTime.parse("13:08:00");

        // apply compareTo()
        int value = time1.compareTo(time2);

        // print LocalDateTime
        System.out.println("Int Value:" + value);

        if (value > 0)
            System.out.println("LocalTime1 is greater");
        else if (value == 0)
            System.out.println("LocalTime1 is equal to"
                               + " LocalTime2");
        else
            System.out.println("LocalTime2 is greater");
    }
}

Output:

Int Value:1
LocalTime1 is greater

Program 2: When passed LocalTime is greater

// Java program to demonstrate
// LocalTime.compareTo() method

import java.time.*;

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

        // create a LocalTime Objects
        LocalTime time1
            = LocalTime.parse("07:12:29");
        LocalTime time2
            = LocalTime.parse("13:08:00");

        // apply compareTo()
        int value = time1.compareTo(time2);

        // print LocalDateTime
        System.out.println("Int Value:" + value);

        if (value > 0)
            System.out.println("LocalTime1 is greater");
        else if (value == 0)
            System.out.println("LocalTime1 is equal to"
                               + " LocalTime2");
        else
            System.out.println("LocalTime2 is greater");
    }
}

Output:

Int Value:-1
LocalTime2 is greater

Program 3: When both Localtimes are equal

// Java program to demonstrate
// LocalTime.compareTo() method

import java.time.*;

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

        // create a LocalTime Objects
        LocalTime time1
            = LocalTime.parse("13:08:00");
        LocalTime time2
            = LocalTime.parse("13:08:00");

        // apply compareTo()
        int value = time1.compareTo(time2);

        // print LocalDateTime
        System.out.println("Int Value:" + value);

        if (value > 0)
            System.out.println("LocalTime1 is greater");
        else if (value == 0)
            System.out.println("LocalTime1 is equal to"
                               + " LocalTime2");
        else
            System.out.println("LocalTime2 is greater");
    }
}

Output:

Int Value:0
LocalTime1 is equal to LocalTime2

Reference: https://docs.oracle.com/javase/10/docs/api/java/time/LocalTime.html#compareTo(java.time.LocalTime))