Consider the case where you need to write some code to perform some discrete task, like reading input from the user, or outputting something to a file, or calculating a particular value. When implementing this code, you essentially have two options: Write the code as part of an existing function …
In prior lessons, we’ve covered two different ways to pass an argument to a function: pass by value () and pass by reference (). Here’s a sample program that shows a std::string object being passed by value and by reference: #include <iostream> #include <string> void printByValue(std::string val) // The function …
In the previous lessons, we introduced lvalue references () and lvalue references to const (). In isolation, these may not have seemed very useful — why create an alias to a variable when you can just use the variable itself? In this lesson, we’ll finally provide some insight into what …
Author’s note Sorry for the inconvenience, but this lesson was deprecated when the rewrite of Chapter 9 was deployed on Jan 18, 2021. The content of this lesson has been integrated into lesson .
The void pointer, also known as the generic pointer, is a special type of pointer that can be pointed at objects of any data type! A void pointer is declared like a normal pointer, using the void keyword as the pointer’s type: void* ptr {}; // ptr is a void …
Author’s note Sorry for the inconvenience, but this lesson was deprecated when the rewrite of Chapter 9 was deployed on Jan 18, 2021. The content of this lesson has been integrated into lesson .
Member selection for structs and references to structs In lesson , we showed that you can use the member selection operator (.) to select a member from a struct object: #include <iostream> struct Employee { int id {}; int age {}; double wage {}; }; int main() { Employee joe …
In C++, a reference is an alias for an existing object. Once a reference has been defined, any operation on the reference is applied to the object being referenced. This means we can use a reference to read or modify the object being referenced. Although references might seem silly, useless, …
Consider the following code snippet: int main() { int x { 5 }; int* ptr { &x }; // ptr is a normal (non-const) pointer int y { 6 }; ptr = &y; // we can point at another value *ptr = 7; // we can change the value at …
The need for dynamic memory allocation C++ supports three basic types of memory allocation, of which you’ve already seen two. Static memory allocation happens for static and global variables. Memory for these types of variables is allocated once when your program is run and persists throughout the life of your …
