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>


In some of our class examples, we suggested that our objects should have properties like `WorldPosition` - where that character currently exists in the world.


In 3D environments, this is represented as three separate numbers, or _**coordinates**_, typically called `x`, `y`, and `z` 


We could store this as 3 separate variables.  But it is usually much better to package these coordinates together, so they can be used and transferred as a single object.


This means we need to create a new custom type of data.


</Excerpt>


## Creating Structs


We've already seen how to define a new data type using a `class`, but there is an alternative - something called a structure, or `struct`:


```c++
struct Vector3 {
  float x;
  float y;
  float z;
}
```


<Aside>


### What is a `Vector3`?


A _**vector**_ is a term taken from maths - it simply refers to a container for storing a collection of related variables - often numbers.


Vectors are the most common way of representing position and directions within a space.  Therefore, a custom `Vector3` type (sometimes abbreviated to `Vec3`) is typically one of the most fundamental types within programs that are designed to simulate some physical environment.


The 3 in the type name indicates it is a 3-dimensional vector, used to store a position in a 3D environment.


We build out our knowledge and application of vectors in several lessons throughout the rest of the course.


</Aside>


<Quiz title="Defining Structs">


<Question>


How could we create a struct that represents a combat ability?


<Answer>


```c++
//<qa>
auto Ability {
  int MinDamage;
  int MaxDamage;
  float CritChance;
};
```


<Feedback>


This syntax isn't quite right. Remember the key term we use to define a structure in C++. Think about how we've defined structures in the lesson and the specific keyword that was used.


</Feedback>


</Answer>


<Answer isCorrect>


```c++
//<qa>
struct Ability {
  int MinDamage;
  int MaxDamage;
  float CritChance;
};
```


<Feedback>


You got it!


</Feedback>


</Answer>


<Answer>


```c++
//<qa>
typedef Ability {
  int MinDamage;
  int MaxDamage;
  float CritChance;
};
```


<Feedback>


This syntax is not used for defining structures. 'typedef' serves a different purpose in C++ which we'll cover later. Recall the specific keyword used for defining a new data type like the one we're trying to create.


</Feedback>


</Answer>


</Question>


</Quiz>


<Ad />


## Structs vs Classes (Technical)


You may be thinking this problem could also be solved by classes.  This is completely true - `Vector3` could indeed be a class.


In C++, structs and classes are almost identical.  The only difference between a struct and a class is that, by default, members of a `struct` are `public` whilst in a `class`, they are `private`.


Aside from that, there is no difference - we create and use structs in the same way we do classes. Structs can have functions, constructors, destructors, and everything else that a class has.


Everything we have learned (and will learn in the future) about classes also applies to structs.


## Structs vs Classes (Semantic)


Even though structs and classes are technically almost identical, the C++ community still attaches semantic differences to the two concepts.


The general sentiment is that structs are for creating simpler types, whilst classes are for creating more powerful types.


Google's style guide offers a good example, and many developers/companies have a similar approach:


<Quote author="Google Style Guide" url="https://google.github.io/styleguide/cppguide.html#Structs_vs._Classes">


`structs` should be used for passive objects that carry data, but lack any functionality other than access/setting the data members.


All fields must be `public`, and accessed directly rather than through getter/setter methods.


Methods should not provide behavior but should only be used to set up the data e.g., constructor, `Initialize()`, `Reset()`.


If more functionality is required, a `class` is more appropriate. If in doubt, make it a `class`.


</Quote>


Moreover, the difference between classes and structs may become slightly more important when working within the context of other ecosystems, such as a game engine.


For example, in Unreal Engine, structs have legitimate technical limitations that effectively enforce the "structs are for simple things" convention. 


<Quiz title="Structs vs Classes">


<Question>


What is the main difference between a struct and a class?


<Answer>


There is no difference


<Feedback>


This isn't quite accurate. While structs and classes are very similar in C++, there is a key difference in their default member access specifiers.


</Feedback>


</Answer>


<Answer>


Classes are more powerful - structs are more lightweight.


<Feedback>


This is a common misconception. Consider the technical aspects of structs and classes, particularly focusing on the accessibility of their members by default.


</Feedback>


</Answer>


<Answer isCorrect>


The members of a class are `private` by default - the members of a struct are `public`.


<Feedback>


Correct! This is the fundamental difference between structs and classes in C++.


</Feedback>


</Answer>


<Answer>


Objects can be created from a `class` - structs are entirely "static".


<Feedback>


This isn't correct. Think about the instances we can create from both structs and classes. Remember, the key difference lies in the default access specifiers of their members.


</Feedback>


</Answer>


</Question>


</Quiz>


## Aggregate Initialization


Aggregate initialization is a feature that simplifies the process of initializing simple objects.


It allows us to initialize the members of a struct or an array directly without needing to explicitly define a constructor. 


Consider our earlier `Vector3` struct:


```c++
struct Vector3 {
  float x;
  float y;
  float z;
};
```


In a typical scenario, you would need to define a constructor to initialize these values. However, with aggregate initialization, you can directly assign values to `x`, `y`, and `z` when creating an instance of `Vector3`. Here's what it looks like:


```c++
struct Vector3 {
  float x;
  float y;
  float z;
};

int main() {
  Vector3 Position {1.9, 2.6, 0.3};//<h>
}
```


In this example, `Position` is an instance of `Vector3` with `x`, `y`, and `z` initialized to `1.9`, `2.6`, and `0.3` respectively.


Aggregate initialization is not always available.  We cover it in detail in the advanced course, but for now, we should note that it is more likely to be an option when our types are simple.


As such, if we're adopting the convention of structs being for simple types, aggregate initialization is much more likely to be available to instantiate structs than classes.


With a type that uses more advanced features - such as `private` sections - aggregate initialization is less likely to be an option, and we need to go back to defining an appropriate constructor manually.


## Summary


In this lesson, we explored the concept of structs in C++, exploring their technical and semantic differences from classes. Here are the key takeaways:

- Structs offer a simpler alternative to classes for bundling data together.
- By default, members of a struct are public, unlike in a class where they are private. This is the only technical difference between the two.
- Structs are generally used for passive objects that carry data, without complex behaviors or functionalities.
- Aggregate initialization allows for the simple and direct assignment of values to the members of a struct, enhancing code brevity and clarity.
- The concept of vectors, specifically **`Vector3`**, was introduced as a fundamental type in graphics applications, demonstrating a practical use of structs.

<Preview>


### Operator Overloading


Previously, we've seen how built-in objects like `int` and `bool` allowed us to use operators like `+` and `>=` to interact with them.


```c++
int SomeInt { 2 };
int AnotherInt { SomeInt + 5 };
bool SomeBool { AnotherInt >= 10 };
bool AnotherBool { !SomeBool };
```


It would be useful if we had a way to define operators for our custom types too.  For example, we'll need the ability to add two of our vectors together.


We could define a function on our class or struct to facilitate that.  It could allow us to add vectors together by doing something like this:


```c++
MyFirstVector.Add(MySecondVector);
```


But our code would be more expressive if we could just do this instead:


```c++
MyFirstVector + MySecondVector;
```


In the next lesson, we can see how we can update our classes and structs to make these types of interactions possible.


</Preview>

Moved earlier in the course and refreshed content

Fixed minor syntax error in preview section

Struct declaration - cppreference.com

Differences between a structure and a class in C++

Aggregate initialization

Extended Aggregate Initialisation in C++17--Jonathan Boccara

{CPP}Learn how structs differ from classes and how to use them in this detailed lesson.

Structs and Aggregate Initialization

Understanding the Basics

Practical Applications

Common Mistakes

Next Steps

Additional Resources

Assessment Preparation

Intro to C++ Programming