<aside> 💡 Key concepts:

• Basic data types: numbers and strings
• Classes and data
• Classes and functions

Learning outcomes:

• Select appropriate data types to represent a dataset in a C++ program
• Describe how a class can be used to combine multiple pieces of data into one unit
• Write a class with functions </aside>

2.1. Concepts

Basic Data Types: Numbers and Strings

C++ has several built-in data types for representing numbers and strings:

• Integer types: short, int, long, long long
• Floating-point types: float, double, long double
• Character types: char, wchar_t, char16_t, char32_t
• String type: std::string
• *signed** and *unsigned**:

When used with integers, signed means that the variable can store positive and negative numbers, while unsigned means that the variable can store only non-negative numbers. For example, an unsigned int can store values between 0 and 4294967295, while a signed int can store values between -2147483648 and 2147483647.

Classes and Data

A class is a user-defined data type that combines data members and member functions into a single unit. Classes are the foundation of object-oriented programming.

• Data members (also called instance variables or attributes) hold the state of an object.
• Member functions (also called methods) define the behavior of an object.

Classes and Functions

A class can have different types of member functions:

• Constructors: Special member functions that are called when an object is created. They initialize the object's data members.
• Destructor: A special member function that is called when an object is destroyed. It cleans up resources used by the object.
• Accessor functions: Member functions that provide read access to the object's data members.