📅 Date: Jan 9, 2026
🔥 Topic: Value vs Reference Diff & Default Arguments

⚔️ The Comparison

Yesterday I learned the code logic. Today I dug deeper into why and when to use which.

Feature Pass by Value Pass by Reference (&)
Memory Creates a copy (More memory). Uses original memory (Efficient).
Safety Original data is safe. Original data can be modified.
Speed Slower for large objects. Faster (No copying involved).

✨ Small Concept: Default Arguments

I also learned a cool trick called Default Arguments. We can give parameters a default value, so if we don't pass anything, it uses the default one.

Rule: Default arguments must be at the end of the parameter list. 

#include <iostream>
using namespace std;

// 'money' has a default value of 100
void treat(string name, int money = 100) {
    cout << name << " treats with Rs " << money << endl;
}

int main() {
    treat("Sahil", 500); // Uses 500
    treat("Rohan");      // Uses default 100!
    
    return 0;
}

💭 Thoughts

C++ gives you a lot of control. Default arguments are super useful for making flexible functions. Tomorrow is the big day—I start Arrays!