References
This article is quite advanced and assumes you have an understanding of C++. If not, please refer to the C++ section of this book!
While not a pointer type, references are often used in C++ as an alternative to pointers for providing an alias to an existing variable (a way to access that variable through a different name). They must be initialized when declared and cannot be reassigned.
int someVar = 69;
int& someReference = someVar;
References offer some benefits, such as:
- Unlike pointers, references cannot be null, eliminating the need to check for null values. This can lead to safer code by avoiding null pointer-related issues.
- References are often more convenient to use than pointers because they don’t require dereferencing syntax (
*) and can be used similarly to the original variable. - References provide a convenient and readable way to create aliases for variables. They act as additional names for the same piece of memory.
- When passing variables to functions or returning values from functions, using references can avoid unnecessary copying of data. This can be more efficient, especially for large objects such as arrays.
- They allow functions to modify the values of variables passed to them. This is useful for functions that need to update multiple variables or modify their parameters.
- References improve code readability by creating expressive and self-documenting code. The use of references indicates that the variable is being referenced or modified within a function.
- References are commonly used in operator overloading, allowing you to define custom behaviors for operators like +, -, etc.
#include <iostream>
void ModifyValue(int& ref)
{
// Modifying the value directly through the reference
ref = 42069;
}
int main()
{
int someVar = 69;
// Creating a reference to the variable
int& someRef = someVar;
std::cout << "Original Variable: " << someVar << std::endl;
std::cout << "Reference: " << someRef << std::endl;
// Modifying the variable through the reference
reference = 420;
std::cout << "Modified Variable: " << someVar << std::endl;
// Passing a variable to a function by reference
ModifyValue(someVar);
std::cout << "Modified Variable after Function Call: " << someVar << std::endl;
return 0;
}