Trust Coding : Programming: 🔹 Structure vs Union in C

🧵 Difference Between Structures and Unions in C

In C programming, both structures and unions are user-defined types that group different variables together. However, the way they handle memory is very different.

🔹 Structure Example

#include <stdio.h>

struct Person {
    int age;
    float height;
};

int main() {
    struct Person p = {25, 5.9};
    printf("Age: %d\n", p.age);
    printf("Height: %.1f\n", p.height);
    return 0;
}

✔️ Each member has its own memory space.

🔹 Union Example

#include <stdio.h>

union Data {
    int age;
    float height;
};

int main() {
    union Data d;

    d.age = 25;
    printf("Age: %d\n", d.age);

    d.height = 5.9;
    printf("Height: %.1f\n", d.height);

    printf("Age after assigning height: %d\n", d.age);

    return 0;
}

⚠️ Assigning a new value overwrites the previous one due to shared memory.

🔹 Comparison Table

Feature	Structure	Union
Memory Allocation	Each member gets its own memory	All members share the same memory
Size	Sum of all member sizes	Size of the largest member
Access	Access all members at once	Access one member at a time
Use Case	Store multiple values	Store a single value at a time
Memory Efficiency	Less efficient	More efficient

🔹 When to Use

Structure: When you need all the data fields together (e.g., name, age, marks).
Union: When only one value is needed at a time (e.g., sensor data format).

🔚 Summary

Use structures when you want to store and access multiple members independently. Use unions when memory is limited and only one member is needed at a time.

Trust Coding : Programming

🔹 Structure vs Union in C