- Trending Categories
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
How do we compare the members of enums in Java?
Enumeration (enum) in Java is a datatype which stores a set of constant values. You can use enumerations to store fixed values such as days in a week, months in a year etc.
enum Days {
SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY
}You can also define an enumeration with custom values to the constants declared. But you need to have an instance variable, a constructor and getter method to return values.
You can compare the members of two enums using the “==” operator or the equals() method.
Comparing enum members using “==”
- If you compare two enum members with the “==” operator, both must be of same type else a compile time error is generated.
enum Vehicles {
ACTIVA125, ACTIVA5G, ACCESS125, VESPA, TVSJUPITER;
}
enum Scoters {
ACTIVA125, VESPA, TVSJUPITER, ACTIVA5G, ACCESS125,;
}
public class EnumComparison {
public static void main(String args[]) {
Vehicles veh[] = Vehicles.values();
Scoters sco[] = Scoters.values();
//comparing enum members of two different types
System.out.println(veh[1]==sco[1]);
}
}Compile time error
EnumComparison.java:14: error: incomparable types: Vehicles and Scoters System.out.println(veh[1]==sco[1]); ^ 1 error
- Using the “==” operator you can compare the members enum that are of same type (only).
Example
Let us create an enum with name Vehicles with 5 constants representing models of 5 different scoters with their prices as values, as shown below −
enum Vehicles {
//Constants with values
ACTIVA125(80000), ACTIVA5G(70000), ACCESS125(75000), VESPA(90000), TVSJUPITER(75000);
//Instance variable
private int price;
//Constructor to initialize the instance variable
Vehicles(int price) {
this.price = price;
}
//Static method to display the price
public int getPrice(){
return this.price;
}
}In the Following Java program, the displayPrice() method accepts a constant of the enum Vehicles and, compares it with all the other constants in Vehicles using the “==” operator and, displaces the value of the particular constant (price) incase of a match.
public class EnumerationExample {
public void displayPrice(Vehicles enum) {
if (enum == Vehicles.ACTIVA125) {
System.out.println("The price of "+enum+" is:"+enum.getPrice());
} else if (enum == Vehicles.ACTIVA5G) {
System.out.println("The price of "+enum+" is:"+enum.getPrice());
} else if (enum == Vehicles.ACCESS125) {
System.out.println("The price of "+enum+" is:"+enum.getPrice());
} else if (enum == Vehicles.VESPA) {
System.out.println("The price of "+enum+" is:"+enum.getPrice());
} else if (enum == Vehicles.TVSJUPITER) {
System.out.println("The price of "+enum+" is:"+enum.getPrice());
} else {
System.out.println("Model not found");
}
}
public static void main(String args[]) {
EnumerationExample obj = new EnumerationExample();
obj.displayPrice(Vehicles.ACTIVA125);
obj.displayPrice(Vehicles.ACTIVA5G);
obj.displayPrice(Vehicles.ACCESS125);
obj.displayPrice(Vehicles.VESPA);
obj.displayPrice(Vehicles.TVSJUPITER);
}
}Output
The price of Activa125 is:80000 The price of ACTIVA5G is:70000 The price of ACCESS125 is:75000 The price of VESPA is:90000 The price of TVSJUPITER is:75000
Comparing enum members using “==”
- You can compare two enum members of same or different type using the equals() method.
enum Vehicles {
ACTIVA125, ACTIVA5G, ACCESS125, VESPA, TVSJUPITER;
}
enum Scoters {
ACTIVA125, VESPA, TVSJUPITER, ACTIVA5G, ACCESS125,;
}
public class EnumerationComparison {
public static void main(String args[]) {
Vehicles veh[] = Vehicles.values();
Scoters sco[] = Scoters.values();
//comparing enum members of two different types
System.out.println(veh[1].equals(sco[1]));
System.out.println(veh[1].equals(veh[1]));
}
}Output
False true
528 Views
