What is the structure of a class implementation in C++?

class Animal{
   string animalName;
   public:
   Animal(string name);
   void animalSound();
   void printName();
};

Member Function Section

Member functions are methods used to access data members of the class.
Definition of member functions can be inside the class or outside the class.
This section contains definition of the member functions that are declared inside the class.

int main(){
   Animal a("Dog");
   a.printName();
   a.animalSound();
}

Class Declaration Section

You can declare class using the keyword class
You can add data members and member functions inside the class.
Accessing the data members and member functions depends solely on the access modifiers, i.e., public, private or protected.
A class always starts with { and ends with };

void Animal :: 
   Animal(string name){
      animalName = name;
   }
   void Animal :: animalSound(){
      cout << "Woof Woof!" << endl;
   }
   void Animal :: printName(){
      cout << animalName << endl;
   }

Main Function Section

Execution of the code starts from main.
In this section, we can create an object of a class.
We can call the functions defined inside the class.

#include <iostream>     // Header files
using namespace std;
class Animal{    // class name
  string animalName;      // class data member
  public:
  Animal(string name);   // Animal constructor
  void animalSound();    // Member function declaration
  void printName();
};
Animal :: Animal(string name){   // function defintion
  animalName = name;
}
void Animal :: animalSound(){
  cout << "Woof Woof!" << endl;
}
void Animal :: printName(){
  cout << animalName << endl;
}
int main(){
  Animal a("Dog");    // creating object of class Animal
  a.printName();  // calling member function 
  a.animalSound();  // calling member function
}

Free Resources

What is the structure of a class implementation in C++?

Structure of a C++ Class

Member Function Section

Class Declaration Section

Main Function Section