References vs Pointers & Const Correctness

Pass-by-reference without pointer syntax and const correctness guarantees

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C++ introduced References (&), which act as permanent aliases to existing objects. Unlike pointers, references cannot be null and cannot be reseated.

References and Const Correctness

Reference (int &ref = original): An alias for an existing variable. Modifying ref modifies original directly.

Pass-by-Const-Reference (const std::string &str): The golden standard in C++! Passes large objects without expensive memory copies while guaranteeing the function cannot modify the original.

Pass-by-Const-Reference in C++

Try It Yourself »

#include <iostream>
#include <string>

// Efficient: Zero string copy, guaranteed read-only
void printBanner(const std::string &text) {
    std::cout << "=== " << text << " ===" << std::endl;
}

int main() {
    std::string title = "Codexia High Performance C++";
    printBanner(title); // Passes lightweight reference
    return 0;
}

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Test Yourself With Exercise

+15 XP

Why is `const std::string &param` the preferred convention for passing strings and objects into C++ functions?

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