📘 Lesson · Lesson 55

Call by Value vs Reference

Two Ways to Pass Arguments

💡 Note

Call by value passes a copy (original unchanged). Call by reference passes the address (original can change).

void change(int x) { x = 100; }
int main() {
    int a = 5;
    change(a);
    printf("%d", a);   // 5 (unchanged)
}

Output:
5

void change(int *x) { *x = 100; }
int main() {
    int a = 5;
    change(&a);
    printf("%d", a);   // 100 (changed)
}

Output:
100

Call by value copies the data; call by reference passes the address so changes persist.

💡 Note

Call by value copy भेजता है (original unchanged)। Call by reference address भेजता है (original बदल सकता है)।

void change(int x) { x = 100; }
int main() {
    int a = 5;
    change(a);
    printf("%d", a);   // 5 (unchanged)
}

Output:
5

void change(int *x) { *x = 100; }
int main() {
    int a = 5;
    change(&a);
    printf("%d", a);   // 100 (changed)
}

Output:
100

Call by value data copy करता; call by reference address भेजता है तो changes रहते हैं।