C++ Functions

C++ Functions

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1. Introduction

Now it's time to dive into the world of C++ functions! Now you will learn some general concepts about functions in C++, including their definition, declaration, and usage. Discover how to declare and call functions, and gain insights into variable scopes, both local and global, for effective program design.

What is Function in C++?

How to Create Function in C++?

Simple Function Creation

Variable Scopes

Understanding Variable Scopes

2. Function Arguments Specification

We will delve into specifying and using function arguments in C++ programming. Explore concepts like pass-by-value and pass-by-reference, and understand the role of default arguments; learn how to pass arrays as function arguments and become familiar with constant function arguments.

Positional and Default Arguments

Passing Arguments by Value/Pointer/Reference

Constant Function Arguments

Passing Static Array as an Argument of the Function

Passing Dynamic Array as an Argument of the Function

Why Do We Need Array Size as an Argument?

Passing Custom Structures as Arguments

3. Function Return Values Specification

Now we will learn about how to specify the return value of a function in C++. This includes understanding the data types that functions can return, such as integers, floating-point numbers, and arrays. We will also consider function that have no return value.

Returning Values With Simple Data Types

Returning Arrays from the Function

Return Custom Data Types

Void Return Type

4. Some Advanced Topics

Now let's delve into some additional topic in C++! We will explore function overloading, mastering the art of creating multiple functions with the same name but different parameter lists for enhanced code flexibility. Recursion is introduced, teaching the principles of recursive functions, allowing students to solve complex problems efficiently. Additionally, the section covers lambda functions, providing insights into creating concise anonymous functions/

Function Overloading

Function Overloading Practice

Lambda Functions

Course Content

C++ Functions

Void Return Type

In C++, the void return type is used in functions to indicate that the function does not return any value. When a function has a void return type, it means the function does its task without producing a result that needs to be used elsewhere in the program.

For example, let's consider the function that prints values of 1D dynamic array that we used before:

main


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#include <iostream>

// Function to print values of a 1D dynamic array
void printArray(const int* arr, const int size) {
    for (int i = 0; i < size; ++i)
        std::cout << arr[i] << " ";
    std::cout << std::endl;
}

int main() 
{
    // Example 1D dynamic array
    int size = 5;
    int* dynamicArray = new int[size] { 1, 2, 3, 4, 5 };

    // Call the function to print the array values
    printArray(dynamicArray, size);

    // Deallocate the dynamically allocated memory
    delete[] dynamicArray;
}

We can see that the purpose of this function is to print the array, and it doesn't produce any meaningful result that must be returned. So we can use void return value in this case.

But you can still use return in a void function. For example if you want to terminate it on certain condition.

main


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#include <iostream>

void displayDivision(double a, double b)
{
    if (b == 0) 
        return;
    std::cout << "displayDivision was called: " << a / b << std::endl;
}

int main() 
{
    // Call the function to print the division result
    displayDivision(15, 8);
    
    // Now second argument is zero
    displayDivision(15, 0); // nothing happens
}

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 4

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