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

In previous lessons, we saw how we could initialize the members of our classes to specific values within the body of a _**constructor**_:


```c++
class Character {
public:
  Character() {
    mHealth = 100;//<h>
  }

private:
  int mHealth;
};
```


<LessonPromo url="intro-to-programming/constructors" title="Constructors and Destructors" description="Learn about special functions we can add to our classes, control how our objects get created and destroyed." />


C++ provides a dedicated syntax for this purpose called a _**member initializer list**_.


## Defining a Member Initializer List


The previous example, where we initialize our `Health` to `100` from the constructor, can instead be written using a member initializer list.  It would look like this:


```c++
class Character {
public:
  Character() : mHealth{ 150 } {//<h>
    // Body here
  }

private:
  int mHealth;
};
```


We place the initializer list between the name and the body of the function, separated by a `:`.


We still provide a function body for our constructor, within a set of `{` and `}` as usual.  It can be blank as in the above example, or we can put any other code we might need in there.


<Quiz title="Using a Member Initialiser List">


<Question>


How can we update the following class to use a member initializer list?


```c++
class Weapon {
public:
  Weapon() {
    mDamage = 150;
  }

  int mDamage;
};
```


<Answer>


```c++
//<qa>
class Weapon {
public:
  Weapon() : mDamage { 150 };

  int mDamage;
};
```


<Feedback>


We still need to provide the braces for a function body, even if we do not need to put any code in there.


</Feedback>


</Answer>


<Answer isCorrect>


```c++
//<qa>
class Weapon {
public:
  Weapon() : mDamage { 150 } {}

  int mDamage;
};
```


<Feedback>


Excellent! You've correctly used the member initializer list to initialize `mDamage`.


</Feedback>


</Answer>


<Answer>


```c++
//<qa>
class Weapon {
public:
  Weapon(int Damage = 150) {
    mDamage = Damage;
  };

  int mDamage;
};
```


<Feedback>


This approach still uses the constructor body for initialization. Reflect on how a member initializer list is structured and try again, focusing on initializing directly in the list.


</Feedback>


</Answer>


</Question>


</Quiz>


## Why use a Member Initializer List?


Member initializer lists have three main advantages over writing equivalent code in the constructor body:


### Performance


Due to nuance in how objects are constructed, initializing variables in a constructor body is slightly slower than it needs to be. 


When our object is created, memory is assigned for its variables, and initially set to some default value.  This happens before our constructor body is executed.  If our constructor body then changes the value of those variables, we have to revisit and update those memory locations.


By specifying initial values in a dedicated initializer list, the compiler can identify and optimize that process to a single step.


### Code Readability


Member initializer lists are dedicated to initializing our class members.


Once we get familiar with the syntax, this means we will immediately understand what that part of the code is doing when scanning through files.


### It's Sometimes Required


In some scenarios, using a member initializer list is required to get the desired functionality.  We'll see an example of this in the next lesson, and more examples later in the course.


## Initializing Multiple Members


If we want to initialize multiple class variables, we can add those to the list, separated by commas:


```c++
class Character {
public:
  Character() : mHealth{ 150 }, mLevel{ 5 } {//<h>
    // Body here
  }

private:
  int mHealth;
  int mLevel;
};
```


## Using Expressions in Member Initializer Lists


Like with the initialization of any other variables, any expression that results in a value of the correct type can be used.  This is shown in the below example.


Remember, C++ is not especially sensitive to white space, so we can generally add line breaks and additional space where needed if we think it makes our code more readable:


```c++
int GetLevel() { return 5; }

class Character {
public:
  Character() :
    mHealth{ 100 + 50 },//<h>
    mLevel{ GetLevel() }//<h>
  {
    // Body here
  }

private:
  int mHealth;
  int mLevel;
};
```


## Using Parameters in Member Initializer Lists


Of course, the above examples are slightly unnecessary.  The previous examples don't need an initializer list or a constructor at all - we could just do this:


```c++
class Character {
  int mHealth { 100 + 50 };
  int mLevel { GetLevel() };
};
```


However, the strength of initializing variables from constructors is that we can use the arguments provided to the constructor.  Below, we have a request to create two `Character` objects, where each request is passing two arguments to a hypothetical constructor:


```c++
Character SmallCharacter { 150, 5 };
Character BigCharacter { 300, 15 };
```


With member initializer lists, we can set our constructor up to support this as follows:


```c++
class Character {
public:
  Character(int Health, int Level) ://<h>
    mHealth{Health},//<h>
    mLevel{Level}//<h>
  {
    // Body here
  }

private:
  int mHealth;
  int mLevel;
};
```


<Quiz title="Using a Member Initializer List">


<Question>


How can we update the following class to use a member initializer list?


```c++
class Weapon {
public:
  Weapon(int Damage) {
    mDamage = Damage;
  }

  int mDamage;
};
```


<Answer isCorrect>


```c++
//<qa>
class Weapon {
public:
  Weapon(int Damage): mDamage { Damage } {}

  int mDamage;
};
```


<Feedback>


Great job! You've correctly updated the class to use a member initializer list.


</Feedback>


</Answer>


<Answer>


```c++
//<qa>
class Weapon {
public:
  Weapon(int Damage): Damage { mDamage } {}

  int mDamage;
};
```


<Feedback>


The order is slightly wrong here - this is trying to initialize a variable called `Damage` with a parameter called `mDamage`. This will not compile, as neither the variable nor the parameter exists.


</Feedback>


</Answer>


<Answer>


```c++
//<qa>
class Weapon {
public:
  Weapon(int mDamage = Damage) {}

  int mDamage;
};
```


<Feedback>


This approach seems to confuse the parameter with the class member. Remember, in the initializer list, we directly initialize the class member with the given parameter.


</Feedback>


</Answer>


<Answer>


```c++
//<qa>
class Weapon {
public:
  Weapon(int Damage = 150) {
    mDamage = Damage;
  }

  int Damage;
};
```


<Feedback>


This attempt doesn't use a member initializer list and instead uses the constructor body. Try to use the member initializer list to set the class member directly.


</Feedback>


</Answer>


</Question>


</Quiz>


<Ad />


## Summary


In this lesson, we explored the use of Member Initializer Lists. We learned that these lists offer a more efficient way to initialize class members, enhancing both performance and code readability. Key points include:

- Member Initializer Lists allow for direct initialization of class members.
- They provide performance benefits by reducing the number of operations during object creation.
- These lists enhance code clarity, making the initialization intent explicit.
- In certain scenarios, Member Initializer Lists are necessary for correct class functionality.
- We can initialize multiple members and use expressions and constructor parameters in these lists.

<Preview>


### Working with Inherited Members


Next, we'll explore working with inherited members in more depth.


This lesson will broaden our understanding of class inheritance in C++, focusing on how to effectively initialize and manipulate inherited class members. We'll cover:

- Techniques for calling inherited constructors to ensure proper initialization of base class members.
- Methods for modifying inherited variables, tailoring them to fit the needs of derived classes.
- Strategies for replacing and extending inherited functions to add or alter functionality in derived classes.
- Exploring the nuances and best practices of working with inheritance in C++.

</Preview>

Removed superfluous semicolons in `Using a Member Initializer List` quiz

3D art showing a female blacksmith character

Constructors and member initializer lists

Why should I prefer to use member initializer lists?

Member initializer lists

Member initialization in constructors

FAQ: Constructors and Member Initializer Lists

{CPP}Understand Member Initializer Lists, and how they speed up object creation

{CPP}Mastering C++: Intro to Member Initializer Lists

Using Expressions in Member Initializer Lists

Using Parameters in Member Initializer Lists

Member Initializer Lists

Understanding the Basics

Practical Applications

Common Mistakes

Next Steps

Additional Resources

Assessment Preparation

Intro to C++ Programming