#1.Journey to  DSA in C++

#1.Journey to DSA in C++

Understanding Pass by Reference and Pass by Value in C++


3 min read

Unlocking the Power of Data Structures and Algorithms in C++: A Journey Through pass by value and pass by reference

"Hey there! ๐ŸŒŸ It's Joyshree ๐Ÿ‘‹, and I'm absolutely stoked to kickstart my journey into the wonderful world of Data Structures and Algorithms (DSA) using C++. ๐Ÿš€ In thissession, we'll dive into the basics, the building blocks of my DSA adventure. So, grab your thinking caps ๐Ÿงข and let's get started!"

Demystifying Data Structures and Algorithms (DSA) with C++

Welcome to another insightful journey into the world of Data Structures and Algorithms in C++. In today's blog post, we will unravel the concepts of "pass by value" and "pass by reference." These fundamental concepts are essential for anyone aspiring to become a proficient C++ programmer. So, let's dive right in!

Table of Contents

  1. Introduction

  2. Pass by Value

  3. Pass by Reference

  4. When to Use Which?

  5. Conclusion


In the realm of C++ programming, understanding how data is passed to functions is crucial. This directly impacts the efficiency and behavior of your code. Two common mechanisms for passing data to functions in C++ are "pass by value" and "pass by reference." Let's explore each of them.

Pass by Value

Pass by value is a method of passing data to a function where a copy of the actual parameter is created. In other words, the function receives a duplicate of the data, and any changes made within the function do not affect the original data outside the function.

void modifyValue(int x) { x = x + 10; }

int main() { int num = 5; modifyValue(num); // num remains 5 return 0; }

In this example, num remains unchanged because modifyValue works with a copy of num.

Pass by Reference

Pass by reference, on the other hand, allows a function to directly access and modify the original data without creating a copy. To achieve this, you use references as function parameters.

void modifyReference(int &x) { x = x + 10; }

int main() { int num = 5; modifyReference(num); // num is now 15 return 0; }

Here, modifyReference modifies the original num since it's passed by reference.

When to Use Which?

The choice between pass by value and pass by reference depends on your specific requirements:

  • Pass by Value: Use when you want to work with a local copy of the data without affecting the original. This is suitable for functions that shouldn't alter the original data.

  • Pass by Reference: Use when you need to modify the original data within the function. It's more efficient since it avoids unnecessary data copying.


Understanding the nuances of "pass by value" and "pass by reference" is pivotal in C++ programming. It not only impacts the behavior of your code but also influences its efficiency. Knowing when to choose one over the other can greatly enhance your programming skills.

Happy coding! ๐Ÿ˜Š๐Ÿš€