Enumeration in C++ : 

Enumeration in another kind of user-defined datatype in C++. It is generally used to store constant values or set of constant values. It also makes a program easy to read and maintain. It is denoted with the keyword " enums ".

Syntax to define an enum : 

enum enum_name{const1, const2, ....... };

If this data-type is used for any variable then that variable becomes enum type and will be storing the constants or set of constants.

Each enum constant has a default value starting from 0 to n but it can be changed manually too while writing program 

For Example :- 

enum season_names{Winter, Summer, Monsoon, Spring};

In the above example the default value of Winter is 0 followed by Summer which is 1 and followed by other seasons. Now in order to change the default values we have to declare the values explicitly in the enum. 

For Example :- 

enum season_names{Winter = 2, Summer = 5, Monsoon = 3, Spring = 4};

Now we got to know how to define an enum, so now we will see how to get / use the values or elements of enums in any program. 
 
In order to use the values or elements of enums there are different ways to declare an enum variable the ways are given below : - 

// enum defined
enum season_names{Winter, Summer, Monsoon, Spring};

// declaring enum variable 
season_names s1 = Monsoon;
season_names s2(Spring);
season_names s3{Winter};

cout<<"season name is "<<s1;
cout<<"season name is "<<s2;
cout<<"season name is "<<s3;

#include<iostream>
using namespace std;

int main()
{
    enum colour //defining an enum called colour
    {
        violet, //by default value o is assigned
        indigo, //value is incremented by 1, hence value assigned is 1
        blue,   //value assigned is 2
        green,  // value assigned is 3
        yellow, // value assigned is 4
        orange, //value assigned is 5
        red     // value assigned is 5
    };          // the defining of an enum must end with a semicolon
    //different ways of defining variables of enumeration type colour
    colour c1 = green;
    colour c2(orange);
    colour c3{blue};
    cout << "The value of colour 1 is: " << c1 << endl;
    cout << "The value of colour 2 is: " << c2 << endl;
    cout << "The value of colour 3 is: " << c3 << endl;
    return 0;
}