Why to use enum in Java?

In Java programming, an enum (quick for enumeration) is a special facts kind that permits you to define a fixed of named constants. Enum constants are essentially predefined values that can be used to symbolize a particular set of values, like the days of the week, the months of the year, or the states of a selected technique. Enum in Java offer some of blessings over the use of raw values or constants. In this newsletter, we're going to discover why you ought to keep in mind the usage of enum for your Java code, and offer a few examples of how they can be used to enhance your applications.

1. Improved Readability and Maintainability

One of the principle advantages of the use of enum in Java is they make your code greater readable and maintainable. By defining a hard and fast of named constants, you could give meaningful names to values that could in any other case be unclear or hard to don't forget. For example, consider the following code that makes use of uncooked integer values to represent the days of the week:

While this code works, it may be difficult to don't forget what every value represents, in particular in case you're running with a person else's code. By the use of enum, you may deliver meaningful names to each price:

It makes the code much easier to read and understand, especially if you're not familiar with the codebase.

Here's an example program that demonstrates the use of enum for days of the week:

EnumExample.java

Output:

Today is WEDNESDAY

2. Type Safety

Another advantage of the use of enum in Java is that they offer kind safety. With raw values or constants, it's viable to skip in a value that does not make sense for a particular variable or technique. For instance, recall the following code that makes use of uncooked integer values to represent the months of the year:

If we call the printMonth method with the argument 1, it will print:

If we call the printMonth method with the argument 2, it will print:

If we call the printMonth method with the argument 12, it will print:

If we call the printMonth method with any other argument, it will throw an IllegalArgumentException with a message indicating the invalid month value.

The code works, but it's possible to pass in an invalid value for the month parameter (e.g. 13). With enum, this isn't possible:

Output:

MAY

The code defines the Month enum with all 365 days indexed so as. The printMonth technique takes a Month argument and prints its name to the console. The fundamental technique calls printMonth with the Month.MAY argument and feedback out the road that would reason a compilation mistakes if uncommented. This suggests that the printMonth method efficiently prints the call of the Month argument surpassed to it. If we uncomment the second call to printMonth, this system will not collect because thirteen isn't a legitimate Month cost. This demonstrates the safety and correctness provided with the aid of using enum in preference to integers or constants. In the second version of the code, the `printMonth` method takes an issue of type `Month`, that could best take one of the twelve legitimate values described within the enum. If you try and pass an invalid value, the code may not bring together, giving you an early caution that something is inaccurate.

3. Enum Constants Can Have Properties and Methods

In addition to being named constants, enum constants in Java also can have homes and techniques. This can be useful whilst you want to partner extra information or behavior with a particular regular. For instance, consider the subsequent code that defines an enum for the planets within the solar system:

EnumExample.java

Output:

The mass of Earth is 5.976E24 kilograms
The radius of Earth is 6.37814E6 meters
The surface gravity of Earth is 9.819299216187818 m/s^2

In this case, each planet in the enum has a mass and radius associated with it, and a constructor that units those values. The enum additionally has a static final regular for the familiar gravitational consistent `G`, and a technique to calculate the surface gravity of every planet based totally on its mass and radius.

The `fundamental` method demonstrates a way to use those properties and techniques with an instance of the `Planet` enum.

4. Enum Can Implement Interfaces

In Java, enum can implement interfaces, just like everyday instructions can. This can be useful while you need to institution related constants collectively and provide them a not unusual behavior. Here's an instance that shows a way to use an enum to define one of a kind varieties of sorting algorithms:

EnumExample.java

Output:

Before sorting: [5, 2, 8, 4, 7]
After sorting with bubble sort: [2, 4, 5, 7, 8]

In this example, the Sorter interface defines a kind approach that takes an array of integers and sorts it in ascending order. The SortingAlgorithm enum implements this interface and defines three sorting algorithms: bubble type, insertion type, and choice kind. The predominant method demonstrates a way to use the type method with an example of the SortingAlgorithm enum.

In Summary, enum in Java are a powerful tool for defining named constants with type safety, stopping programming errors, and including additional records and conduct to your constants. By the use of enum, you could make your code greater readable, maintainable, and sturdy.