Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Comparing enum members in Java
The java.lang.Enum class is the common base class of all Java language enumeration types.
Class Declaration
Following is the declaration for java.lang.Enum class -
public abstract class Enum<E extends Enum<E>> extends Object implements Comparable<E>, Serializable
We can compare enum variables using the following ways.
Using Enum.compareTo() method. compareTo() method compares this enum with the specified object for order.
Using Enum.equals() method. equals() method returns true if the specified object is equal to this enum constant.
Using == operator. The == operator checks the type and makes a null-safe comparison of the same type of enum constants.
Example
public class Tester {
// enum showing topics covered under Tutorials
enum Tutorials {
TOPIC_1, TOPIC_2, TOPIC_3;
}
public static void main(String[] args) {
Tutorials t1, t2, t3;
t1 = Tutorials.TOPIC_1;
t2 = Tutorials.TOPIC_2;
t3 = Tutorials.TOPIC_3;
//Comparing using compareTo() method
if(t1.compareTo(t2) > 0) {
System.out.println(t2 + " completed before " + t1);
}
if(t1.compareTo(t2) < 0) {
System.out.println(t1 + " completed before " + t2);
}
if(t1.compareTo(t2) == 0) {
System.out.println(t1 + " completed with " + t2);
}
//Comparing using ==
//In this case t1 can be null as well causing no issue
if(t1 == Tutorials.TOPIC_1) {
System.out.println("t1 = TOPIC_1");
}else {
System.out.println("t1 != TOPIC_1");
}
//Comparing using equals() method
//In this case t2 cannot be null. It will cause
//null pointer exception
if(t2.equals(Tutorials.TOPIC_2)) {
System.out.println("t2 = TOPIC_2");
}else {
System.out.println("t2 != TOPIC_2");
}
Tutorials t4 = null;
//Comparing using equals() method
//in null safe manner
if(Tutorials.TOPIC_3.equals(t4)) {
System.out.println("t4 = TOPIC_3");
}else {
System.out.println("t4 != TOPIC_3");
}
}
}Output
TOPIC_1 completed before TOPIC_2 t1 = TOPIC_1 t2 = TOPIC_2 t4 != TOPIC_3
Updated on: 18-Jun-2020
12K+ Views
Advertisements