cpp cheat sheet

Certainly! Here's a cheat sheet summarizing the key concepts related to classes and objects in C++:

Classes and Objects:
- A class is a user-defined data type that encapsulates data members (variables) and member functions (methods) into a single unit.
- An object is an instance of a class. It represents a specific occurrence of the class and can be used to access its members.

Class Definition:
```cpp
class ClassName {
  // Data members (variables)
  // Member functions (methods)
};
```

Access Specifiers:
- `public`: Members are accessible from anywhere.
- `private`: Members are only accessible from within the class.

Member Functions:
- Member functions are functions defined inside a class.
- They can be declared and defined inside the class declaration or separately outside the class.
- They can access the class's data members and other member functions.
- Member functions can be classified as `public`, `private`, or `protected` based on their access level.

Data Members:
- Data members are variables declared inside a class.
- They can be `public`, `private`, or `protected` based on their access level.
- Data members represent the state or characteristics of an object.

Constructor:
- A constructor is a special member function with the same name as the class.
- It is automatically invoked when an object of the class is created.
- Constructors are used to initialize the object's data members.

Destructor:
- A destructor is a special member function with the same name as the class preceded by a tilde (`~`).
- It is automatically invoked when an object is destroyed or goes out of scope.
- Destructors are used to release resources or perform cleanup operations.

Member Function Definition:
```cpp
return_type ClassName::functionName(parameters) {
  // Function body
}
```

Creating Objects:
```cpp
ClassName objectName;          // Default constructor
ClassName objectName(value);   // Parameterized constructor
ClassName* ptr = new ClassName();  // Dynamic object creation
```

Accessing Members:
- Dot operator (`.`) is used to access members of an object.
- Arrow operator (`->`) is used to access members through a pointer to an object.

Friend Function:
- A friend function is a non-member function that has access to the private and protected members of a class.
- It can be declared inside the class and defined outside the class.

Friend Class:
- A friend class is a class that has access to the private and protected members of another class.
- It is declared using the `friend` keyword inside the class that grants access.

This cheat sheet covers the fundamental concepts related to classes and objects in C++. Understanding and applying these concepts will help you work with object-oriented programming in C++.