Enum

Enum or Enumeration is a special class that contains collection of constant values. Just because all the value stored inside Enum is constant we cannot change its value and every value will be a read-only one. Enum type is a special data type that enables for a variable to be a set of predefined constants. We'll discuss all about these with code examples

Syntax
enum enumName{
    //Constant values
}

CODE

EG 1 . Creating an Enum called Weekdays.

enum weekdays {
    Monday, Tuesday, Wednesday, Thursday, Friday
}

class Program {
    static void main(){
        weekdays today = weekdays.Wednesday;
        if (today == weekdays.Monday) {
            Console.WriteLine("Do Monday Works");
        }
        else if (today == weekdays.Tuesday) {
            Console.WriteLine("Do Tuesday Works");
        }
        else if (today == weekdays.Wednesday) {
            Console.WriteLine("Do Wednesday Works");
        }
        else if (today == weekdays.Thursday) {
            Console.WriteLine("Do Thursday Works");
        }
        else if (today == weekdays.Friday) {
            Console.WriteLine("Do Friday Works");
        }
    }
}

OUTPUT
Do Wednesday Works

CODE EXPLANATION
In the above code, we created a Enum called weekdays where we stored 5 constant values called Monday, Tuesday, Wednesday, Thursday, Friday. Inside main method we created a variable of Enum called today. Just because today is the variable of Enum weekdays, we can only assign any one of the constant value present inside Enum weekdays. Depending on the value stored inside today we are checking certain conditions and proceeding our code further.


EG 2 . Creating an Enum called Seasons.

enum Seasons {
    Winter, Spring, Summer, Fall
}

class Program {
    static void main(){
        Seasons thisMonth = Seasons.Summer;
        if (thisMonth == Seasons.Winter) {
            Console.WriteLine("The Average temperature is 27°C");
        }
        else if (thisMonth == Seasons.Spring) {
            Console.WriteLine("The Average temperature is 30°C");
        }
        else if (thisMonth == Seasons.Summer) {
            Console.WriteLine("The Average temperature is 34°C");
        }
        else if (thisMonth == Seasons.Fall) {
            Console.WriteLine("The Average temperature is 32°C");
        }
    }
}

OUTPUT
The Average temperature is 34°C

CODE EXPLANATION
In the above code, we created a Enum called Seasons where we stored 4 constant values called Winter, Spring, Summer, Fall. Inside main method we created a variable of Enum called thisMonth. Now we can only assign any one of the constant value present inside Enum Seasons. Depending on the value stored inside thisMonth we are checking certain conditions and printing out certain values.


Where to use Enum?
Use enums when you have values that you know aren't going to change, like planets in our solar system, month, days, colors, seasons, deck of cards etc.

Exercises
1. Create an Enum called Planets and store all planets in our solar system inside it.
2. Create an Enum called Colors and load it up with any 10 constant color names.

(Click Here, For more exercises)