What are some examples of const references in C++?

What are some examples of const references in C++?

In C++, a const reference allows you to bind a reference to a constant value, preventing modification. For example:

void printValue(const int &value) {
    std::cout << value << std::endl;
}

Here, value cannot be changed inside the function.

Can you give me another example?

Sure! Here's another example:

void modifyArray(const std::vector<int> &arr) {
    for (const int &num : arr) {
        std::cout << num << " ";
    }
}

In this case, arr is a const reference to a vector, ensuring the original vector isn't modified.

What happens if I try to modify a const reference?

If you try to modify a const reference, the compiler will throw an error. For instance:

void changeValue(const int &value) {
    value = 10; // This will cause a compilation error!
}

You cannot change value because it's declared as a const reference.

Are there any performance benefits to using const references?

Yes, using const references can improve performance by avoiding unnecessary copies of large objects. It allows you to pass objects efficiently while ensuring they remain unchanged.