classes_vs_structs.md

Structs

• Defined with the struct keyword.
• By default, all members inside a struct are public.
• Commonly used to group data.

#include <iostream>

struct MyStruct 
{
  int value; // public by default

  MyStruct(int v) : value(v) {}

  void show() 
  {
    std::cout << "Value: " << value << std::endl;
  }
};

void main() 
{
  MyStruct obj(5);
  obj.show(); // Output: Value: 5
}

Classes

• Defined with the class keyword.
• By default, all members inside a class are private.
• Commonly used for encapsulating data and behavior together.

#include <iostream>

class MyClass 
{
  int value; // private by default

public:
  MyClass(int v) : value(v) {}

  void show() 
  {
    std::cout << "Value: " << value << std::endl;
  }
};

int main() 
{
  MyClass obj(5);
  obj.show(); // Output: Value: 5
}

Similarities

• Both can have data members, member functions, constructors, destructors, nested types, etc.
• Both can be used with inheritance and polymorphism.
• Both can have access specifiers like public, private, and protected.

When to use classes

• Encapsulation: When you want to encapsulate data and behavior together and control the access to the members, using a class makes the intent clear.

• Complex Behavior: If the type you're defining has complex behavior and interactions with other objects, using a class can help you organize the code and emphasize that there's more than just data grouping.

• Object-Oriented Design: If you are working within a clearly object-oriented design, using classes might be more in line with the idioms and expectations of the language and project.