Getting our machines set up for C++ development, and introducing the fundamental building blocks of programming - variables.

Getting our computer set up so we can create and build C++ programs. Then, creating our very first application

Setting up a C++ Development Environment

An introduction to the building blocks of our software - objects, and the variables that can be associated with them.

Objects, Variables and Types

Creating variables to store and update the data that describes our objects.  We also introduce comments, allowing us to describe our code in plain language.

Creating Variables

An introduction to the different types of numbers in C++, and how we can do basic math operations on them.

Numbers

An overview of the fundamental true or false data type, how we can create them, and how we can combine them.

Booleans - `true` and `false` values

Explore how C++ programs store and manage numbers in computer memory, including integer and floating-point types, memory allocation, and overflow handling.

Types and Literals

Creating a tiny program using numbers and booleans, then adding some breakpoints so we can step through our code in a debugger.

Introduction to Debugging

Types and Variables

Discover how we can package our code into reusable functions that we can easily call.  Then, learn how we can use conditionals and loops to control the flow of our program.

An introduction to functions - reusable blocks of code that we can use to break our application into smaller pieces.

Creating and Calling Functions

An introduction to how our function calls create a call stack, and how we can navigate it in a debugger.

The Call Stack and Debugging Functions

Use booleans and if statements to make our functions and programs more dynamic, choosing different execution paths.

Conditional Logic

Learn an alternative way to write conditionals, which is often used when we want to take different paths based on a specific value

Switch Statements

Allow our functions to communicate with their caller by returning values when they complete

Function `return` Statements

Going into more depth on what is happening when a variable is used as a different type

Implicit Conversions and Narrowing Casts

Making our functions more useful and dynamic by providing them with additional values to use in their execution

Function Arguments and Parameters

Learn more about how and when we can access variables, by understanding the importance of the scope in which they exist.

Scope

Understand what function prototypes are, and learn how we can use them to let us order our code any way we want.

Forward Declarations

Learn how we can use loops to iterate over a block of code, executing it as many times as needed.

Loops

Learn how we can use the modulus operator to get the remainder of integer division, and some common use cases.

The Modulus Operator (`%`)

Put everything we've learned in this chapter to the test by creating a C++ version of the Fizz Buzz game.

Fizz Buzz

Learn how the `&&` and `||` operators are optimized with short-circuit evaluation, only evaluating expressions when necessary

Short-circuit Evaluation

Functions, Conditionals and Loops

Classes and structs are the fundamental feature of object oriented programming.  In this chapter, we will see how we can set them up, and how we can use them to create the custom types our program needs.

Learn how to define, instantiate, and utilize classes, understanding how they form the backbone of object-oriented programming.

Abstraction and Classes

A guide to encapsulation, class invariants, and controlling data access with `public` and `private` specifiers.

Encapsulation and Access Specifiers

Learn about special functions we can add to our classes, control how our objects get created and destroyed.

Constructors and Destructors

Discover the role of structs, how they differ from classes, and how to initialize them without requiring a constructor.

Structs and Aggregate Initialization

This lesson introduces operator overloading, a fundamental concept to create more intuitive and readable code by customizing operators for user-defined types

Operator Overloading

This lesson introduces Structured Binding, a handy tool for unpacking simple data structures

Structured Binding

Classes and Structs

See how we can use inheritance to organise our classes into a hierarchy, unlocking a massive range of possibilities for building more complex software

In this lesson, we explore C++ inheritance, guiding you through creating and managing class hierarchies to streamline your code

Inheritance

Learn about `protected` class members in C++, including how and when to use them in your code, especially in the context of inheritance and class design

Protected Class Members

This lesson introduces Member Initializer Lists, focusing on their advantages for performance and readability, and how to use them effectively

Member Initializer Lists

This lesson provides an in-depth exploration of using inherited methods and variables in C++, covering constructor calls, variable modification, and function shadowing

Working with Inherited Members

An introduction to working with memory, and how we represent memory locations using references and pointers

This lesson introduces references, explaining how they work, their benefits, and their role in performance and data manipulation

References

This lesson provides a thorough introduction to pointers in C++, covering their definition, usage, and the distinction between pointers and references

Pointers

Learn about the `this` pointer in C++ programming, focusing on its application in identifying callers, chaining functions, and overloading operators.

The `this` Pointer

Learn about an important consideration when returning pointers and references from functions

Dangling Pointers and References

Memory, References and Pointers

An introduction to polymorphism - the key tool that let us build more complex programs whilst keeping our code simple.

This lesson provides an in-depth look at function overloading in C++, covering its importance, implementation, and best practices

Function Overloading

Explore the concept of static casting in C++, including examples and best practices for converting data types at compile time

Static Casting

This lesson provides an introduction to virtual functions and overrides, focusing on their role in enabling runtime polymorphism

Virtual Functions and Overrides

Get to grips with downcasting in C++, including static and dynamic casts. This lesson provides clear explanations and practical examples for beginners

Downcasting

Polymorphism

Go deeper on what is happening when we build our software.  Learn how we can use the preprocessor to automatically modify our source code before it is compiled, and how the linker connects our program together.

Explore the essential concepts of C++ preprocessing, from understanding directives to implementing macros

Preprocessor Definitions

Discover how the `#include` directive helps us include library features and split our project across multiple files.

The `#include` Directive

Explore how header files and linkers streamline C++ programming, learning to organize and link our code effectively

Header Files

The Preprocessor and the Linker

Discover additional methods and techniques to keep our data and code organised.

Learn the essentials of using namespaces to organize your code and handle large projects with ease

Namespaces

Learn about Enums and how they offer an efficient way to handle predefined values in your code

Enums

This lesson introduces the `using` keyword in C++, focusing on namespaces, enums, and type aliasing

The `using` Keyword

Namespaces and Enums

Learn how to store collections of objects, and take control of how memory is managed

Explore the fundamentals of dynamic arrays with an introduction to `std::vector`

Dynamic Arrays using `std::vector`

Learn how to manage dynamic memory using unique pointers and the concept of memory ownership

Memory Ownership and Smart Pointers

Explore advanced techniques for managing object copying and resource allocation

Copy Constructors and Operators

Learn the techniques and pitfalls of manual memory management in C++

Managing Memory Manually

Arrays and Dynamic Memory

Techniques to simplify our code, making it easier to understand and maintain

This lesson covers how we can ask the compiler to infer what types we are using through the `auto` keyword

Automatic Type Deduction using `auto`

Learn the intricacies of using `const` and how to apply it in different contexts

Constants and `const`-Correctness

This lesson provides an overview of effective commenting strategies, including Javadoc style commenting for automated documentation

Effective Comments and Javadoc

This lesson introduces the concept of Style Guides and ClangFormat, focusing on how to achieve consistency in our code

Style Guides and Automatic Code Formatting

An introduction to static analysis tools, and how they can help beginners learn faster and improve code quality

Static Analysis

Explore the fundamentals of attributes, including `[[nodiscard]]`, `[[likely]]`, and `[[deprecated]]`

Attributes

Clean Code

A collection of lessons covering a variety of topics worth learning as a beginner

This lesson covers the basics of using randomness, with practical applications

Random Number Generation

Learn the basics of the chrono library and discover how to effectively manage durations, clocks, and time points

Dates, Times and Durations

A detailed guide to string formatting using C++20's `std::format()`, and C++23's `std::print()`

String Interpolation

Learn how to overload the `<<` operator, so our custom types can stream information directly to the console using `std::cout`

Overloading the `<<` Operator

This lesson introduces system calls, and how to use them to clear the terminal

System Calls and Terminal Management

This lesson introduces the fundamentals of capturing user input, using `std::cin` and `std::getline()`

User Input in the Terminal

Unravel the fundamentals of bitwise operators and bit flags in this practical lesson

Bitwise Operators and Bit Flags

Odds and Ends

This course is designed for beginners. We'll take you from the fundamentals and lay a solid foundation for creating real-world programs and learning more advanced concepts.

Become a software engineer with C++.  Starting from the basics, we guide you step by step along the way

This course teaches the fundamentals of C++ while instilling habits used by real-world developers. You'll gain practical experience with concepts that are the foundation of all modern programming.

No previous programming experience is needed - we start from the basics.

Start your Journey

We explain every line of code we're using, so you understand exactly what is happening.

Understand Every Line of Code

Everything we create is organised and implemented using modern, professional practices.

Use Professional Best Practices

We don't just explain what we're doing, but also why. This builds transferrable skills, so you can take what you've learnt and apply them to your own projects.

Focus on Transferrable Skills

No paywalls, no ads - the course is completely free with unlimited access

Free and Unrestricted Access

We break complex concepts into manageable steps, making even advanced topics feel approachable.

Step-by-Step Learning

What You'll Learn

Comprehensive course covering advanced concepts, and how to use them on large-scale projects.

Professional C++

If you're already familiar with the basics of C++ and object oriented programming, you may want to skip to the advanced course.  It starts with a quick summary of everything we cover here.

Already Familiar with Programming?

Intro to C++ Programming

<Excerpt>


One of the first things you'll hear when it comes to programming is the concept called **Object-Oriented Programming**. This is a major feature of C++, and it is a commonly adopted pattern for building complex projects.


When designing object-oriented programs, we think of our code in terms of **objects**. Objects are just a digital representation of something our software is trying to represent, or simulate.  They're a way to organize our project into distinct entities.

- If we were making banking software, we might be creating and managing objects that represent customers and currencies.
- For a library, it might be books and employees.
- For video games, it could be dragons, weapons, and magical spells.

This approach not only simplifies the design of complex software but also makes it easier to maintain as the project gets more and more complex.


For instance, in object-oriented design, a game would treat each player, enemy, and piece of the environment as distinct objects. This modular structure mirrors real-world interactions, making our software more intuitive and aligned with how we naturally perceive the world.


</Excerpt>


<Ad />


A way to identify what objects our software might have is to start with a plain language description of what we're building.  For example:

> In Mythic Quest, our heroes enter dungeons and kill monsters to collect magical items

By picking out nouns from this description, we can identify some of the types of objects we might want to be creating. This might be things such as:

- Heroes
- Dungeons
- Monsters
- Items

Just like objects in the real world, objects in programming have _**properties**_ and _**actions that they can perform**_.


In programming, we often call these object properties _**variables**_, and the actions that the objects can perform are called _**functions**_.


For the next few lessons, we'll focus on variables.  We'll look at functions in the next chapter.


<Definition>


### Models and Modeling


The term _**modeling**_ is often used to describe the process of identifying what variables and functions our digital objects need to have.  Modeling is the process of reducing a complex physical object or system into a simplified representation - a _**model**_ - that we can interact with using code.


However, a "model" is also the name given to a 3D art asset, and "modeling" is the activity of creating such assets.


Therefore, in the context of computer graphics where we are frequently using such 3D assets, the terminology is commonly reserved for that meaning instead.


</Definition>


## Variables


Variables are pieces of data that help describe the current state of our object. Let's take one of our monsters as an example. Some things we might need to keep track of for our monster are:

- What is its name?
- Is it alive?
- How much health does it have?
- How much armor/damage resistance does it have?
- Where is it currently located in the world?
- What weapon does it have equipped?

Answers to these questions would be stored as _**variables**_ on each monster object.


<Ad />


## Data Types


We can notice from the list above that there are different _**types**_ of data we might need to store.  For example:

- Whether the monster is alive will only have two possible values - it is either true or it is false
- For information about its health, we might expect that value to be a number.
- For the name, it might be a string of alphabetic characters.
- To store information about what weapon the monster has equipped, our variable might need to store another object entirely - a `Weapon` object, with its own set of variables.

For now, the key point is that each variable stores data of a specific _**type**_.  When creating programs, we need to be aware of the type of data that is being stored in the variables we're working with.  Some common data types in C++ include:


| Data Type | Description                                | Examples               |
| --------- | ------------------------------------------ | ---------------------- |
| `bool`    | A boolean - either true or false           | `true`, `false`        |
| `int`     | An integer - a whole number                | `42`, `5`, `-621`, `0` |
| `float`   | A decimal ("floating point") number        | `3.4`, `-2.71`, `4.0`  |
| `char`    | An individual character                    | `'a'`, `'B'`, `'@'`    |
| `string`  | A collection of characters strung together | `"Hello World!"`       |


<Aside>


### A Note on Strings


From the table above, only the first four of these data types - `boolean`, `int`, `float`, and `char` - are available to us out of the box.


We'll be able to use the `string` type in our future examples, but that's only because the code we include at the top of our file gives us access to that type.


For now, if we ever find we're having issues where we can't seem to create strings, be sure we're using the code structure provided in the previous lesson:


```c++
#include <iostream>//<h>
using namespace std;//<h>

int main() {

}
```


</Aside>


## Variable Names


Once we identify what type of data we want to store in our variable, we next need to give our variable a name - an **identifier** that we will use in our code.


There are some restrictions to these names.  The most notable restriction is that an identifier cannot contain a space, and it cannot start with a number.  But beyond those restrictions, we can mostly call our variables whatever we want.


However, it is strongly recommended that we choose sensible, descriptive names for our variables.


For example, if a variable is intended to store a character's current amount of health, a name like `Health` would be much better than a name like `MyVariable` or `x`.


There's no technical reason why we can't call our variable things like `MyVariable` or `x`.  However, once our code gets more complex, it can be very difficult to follow what's happening if our variables do not have meaningful names.


<Ad />


When we want to use multiple words to describe our variable, there are some conventions to bypass the inability to use spaces.  Common approaches include using underscores or capitalization, for example: `currentHealth`, `CurrentHealth`, or `Current_Health`.


<Quiz title="Variable Naming">


<Question>


What would be a good name for a variable that stores whether or not a character is alive?


<Answer>
`is alive`
<Feedback>


Variable names cannot include spaces


</Feedback>


</Answer>


<Answer isCorrect>


`isAlive`


<Feedback>


You got it!


</Feedback>


</Answer>


<Answer>


`Value`


<Feedback>


We should have our variables' names indicate what they are representing


</Feedback>


</Answer>


</Question>


</Quiz>


Let's revisit our requirements for our monster objects, and map our variables up to a data type and a name.


| Data Type | Variable Name | Description                                         | Example                   |
| --------- | ------------- | --------------------------------------------------- | ------------------------- |
| bool      | `isAlive`     | Is the monster currently alive?                     | `true`                    |
| int       | `Health`      | How much health does the monster have remaining     | `150`                     |
| float     | `Armor`       | How much damage resistance the monster has          | `0.2`                     |
| string    | `Name`        | The monster's name                                  | `"Goblin Warrior"`        |
| position  | `Location`    | Coordinates of where the monster is in the 3D world | `x=45.2, y=152.5, z=90.1` |
| weapon    | `Weapon`      | The monster's currently equipped weapon             | `Steel Axe`               |


The first four data types are things C++ can provide us with.  Simple types like numbers and strings are included with the language by default because they're useful across a wide range of programs.


Data types like `position` and `weapon` are much more specific to our needs.  As such, they're not included as part of the language.  However, C++ gives us the ability to add our own data types, specific to the needs of our project.  We'll see how to do that in Chapter 3.


Until then, we will just use simple booleans, integers, floating-point numbers, and strings, so we can establish the basics.


## Summary


In this lesson, we introduced the basic concept of Object-Oriented Programming, covering:

- **Objects in C++**: Learned as digital representations of entities, essential for organizing complex software.
- **Variables and Functions**: Introduced as properties and actions of objects.
- **Data Types**: Introduced `bool`, `int`, `float`, `char`, and `string`, highlighting C++ as a strongly typed language.
- **Variable Naming**: Discussed the importance of meaningful names for clarity in code.

<Preview>


### Creating Variables


In the next lesson, we'll put this knowledge to practical use.  We will:

- Create and update variables in code
- Understand how data types affect variable declaration
- Introduce comments, allowing us to add plain-language documentation to our code

</Preview>

Removed section on strongly and weakly typed languages

Object-oriented programming

Object-Oriented Programming Concepts

Introduction to Object-Oriented Programming Concepts

C++ For C Programmers, Part A

{UD}Dive into C++ programming with a focus on object-oriented concepts for beginners

Objects, Variables and Types

Understanding the Basics

Practical Applications

Common Mistakes

Next Steps

Additional Resources

Assessment Preparation

Intro to C++ Programming