The compareTo() method of UUID class in Java is used to compare one UUID value with another specified UUID. It returns -1 if this UUID is less than the value, 0 if this UUID is equal to the value, and 1 if this UUID is greater than the value.
Syntax:
UUID_1.compareTo(UUID_2)
Parameters: The method takes one parameter UUID_2 to which the UUID_1 is to be compared.
Return Value: The method returns -1, 0 or 1 depending on whether this UUID_1 is less than, equal to or greater than the other UUID_2.
Below programs illustrate the working of compareTo() method:
Program 1: Checking if both the UUIDs are equal.
// Java code to illustrate compareTo() method import java.util.*; public class UUID_Demo { public static void main(String[] args) { // Creating two UUIDs UUID UUID_1 = UUID .fromString( "5fc03087-d265-11e7-b8c6-83e29cd24f4c" ); UUID UUID_2 = UUID .fromString( "5fc03087-d265-11e7-b8c6-83e29cd24f4c" ); // Displaying the UUID values System.out.println( "UUID_1: " + UUID_1.clockSequence()); System.out.println( "UUID_2: " + UUID_2.clockSequence()); // Comparing both the UUIDs System.out.println( "Comparison Value: " + UUID_1.compareTo(UUID_2)); } } |
UUID_1: 14534 UUID_2: 14534 Comparison Value: 0
Program 2: When UUID_1 is less than UUID_2, the method returns -1.
// Java code to illustrate compareTo() method import java.util.*; public class UUID_Demo { public static void main(String[] args) { // Creating two UUIDs UUID UUID_1 = UUID .fromString( "58e0a7d7-eebc-11d8-9669-0800200c9a66" ); UUID UUID_2 = UUID .fromString( "5fc03087-d265-11e7-b8c6-83e29cd24f4c" ); // Displaying the UUID values System.out.println( "UUID_1: " + UUID_1.clockSequence()); System.out.println( "UUID_2: " + UUID_2.clockSequence()); // Comparing both the UUIDs System.out.println( "Comparison Value: " + UUID_1.compareTo(UUID_2)); } } |
UUID_1: 5737 UUID_2: 14534 Comparison Value: -1
Program 3: When UUID_1 is greater than UUID_2, the method returns 1.
// Java code to illustrate compareTo() method import java.util.*; public class UUID_Demo { public static void main(String[] args) { // Creating two UUIDs UUID UUID_1 = UUID .fromString( "5fc03087-d265-11e7-b8c6-83e29cd24f4c" ); UUID UUID_2 = UUID .fromString( "58e0a7d7-eebc-11d8-9669-0800200c9a66" ); // Displaying the UUID values System.out.println( "UUID_1: " + UUID_1.clockSequence()); System.out.println( "UUID_2: " + UUID_2.clockSequence()); // Comparing both the UUIDs System.out.println( "Comparison Value: " + UUID_1.compareTo(UUID_2)); } } |
UUID_1: 14534 UUID_2: 5737 Comparison Value: 1