🧱 Meet Structures in C — The Art of Grouping Data Like a Pro!

 

“If arrays are the shelves of data, structures are the well-organized cupboards!”

🌟 Introduction

In your C journey so far, you’ve mastered arrays, loops, functions — all neat ways to handle data.
But what happens when one entity (say, a student, a car, or a bank account) has different types of data tied together?
👉 One integer roll number, one float CGPA, one string name — and you want to keep them together logically.

That’s where Structures walk in — the Avengers of C data organization!
Each hero (member) has a different superpower (data type), but together they save you from chaos.

🧩 What is a Structure?

A structure (or struct) is a user-defined data type that lets you group variables of different types under one name.

Here’s the syntax:

struct structure_name {

    data_type member1;

    data_type member2;

    ...

};

For example:

struct Student {

    int roll;

    char name[30];

    float marks;

};

You just told the compiler:

“Hey C, I’m designing my own data type called Student which has an int, a string, and a float.”

🚀 Declaring and Using Structures

Once the structure is defined, you can create variables of that type:

struct Student s1, s2;

Now each s1 and s2 can hold roll, name, and marks.

Let’s fill them up:

#include <stdio.h>
#include <string.h>

struct Student {
    int roll;
    char name[30];
    float marks;
};

int main() {
    struct Student s1;

    s1.roll = 101;
    strcpy(s1.name, "Aditi Sharma");
    s1.marks = 94.5;

    printf("Student Details:\n");
    printf("Roll: %d\n", s1.roll);
    printf("Name: %s\n", s1.name);
    printf("Marks: %.2f\n", s1.marks);

    return 0;
}

🧠 Output

Student Details:

Roll: 101

Name: Aditi Sharma

Marks: 94.50

Simple, right? But very powerful

🕹️ Accessing Structure Members

You access each member using the dot (.) operator when using a normal structure variable.

Example:
student1.roll, student1.name, student1.marks.

If you have a pointer to a structure, use the arrow (->) operator.
(We’ll explore that in the next post.)

⚙️ Initializing Structures

Just like arrays, you can initialize structures directly when declaring them:

struct Student s2 = {102, "Rohan Das", 88.0};

Or initialize later:

struct Student s3;

s3 = (struct Student){103, "Priya Sen", 91.5};

C gives you the freedom to mix and match!

#include <stdio.h>
#include <string.h>

struct Student {
    int roll;
    char name[30];
    float marks;
};

int main() {
    struct Student students[3] = {
        {101, "Aditi", 94.5},
        {102, "Rohan", 88.0},
        {103, "Priya", 91.5}
    };

    for (int i = 0; i < 3; i++) {
        printf("\nStudent %d\n", i + 1);
        printf("Roll: %d\n", students[i].roll);
        printf("Name: %s\n", students[i].name);
        printf("Marks: %.2f\n", students[i].marks);
    }

    return 0;
}

💡 Think of this as a “mini database” — each structure is a record.

🧰 Structure Inside Structure (Nested Structures)

Structures can hold other structures too!

Example:

struct Date {

    int day;

    int month;

    int year;

};

 

struct Student {

    int roll;

    char name[30];

    struct Date dob;  // nested structure

    float marks;

};

Now you can do:

struct Student s1 = {101, "Aditi", {5, 8, 2004}, 94.5};

printf("DOB: %02d-%02d-%d", s1.dob.day, s1.dob.month, s1.dob.year);

🧭 Why Use Structures?

Situation	Without Structures	With Structures
Student info	3 separate variables per student	1 structure per student
Employee record	Messy multiple arrays	Clean and cohesive
Real-world modeling	Hard to manage	Logically grouped

Bottom line: Structures help your code speak object language even in a non-object-oriented world!

⚡ Quick Recap: Structure Superpowers

✅ Can group multiple data types together
✅ Easy to manage, pass, and return from functions
✅ Great for arrays of records
✅ Basis for advanced concepts like Unions, Pointers to Structures, and Files of Structures

💡 Try This Yourself

Mini Challenge:

Write a C program to store details (roll, name, marks) of 5 students and print the topper’s name and marks.

Hint: Use an array of struct Student and a loop to find max marks.

🧠 What’s Next?

In the next post — “Structures in Action — From Student Records to Real-World Models”,
we’ll go hands-on with passing structures to functions, returning structures, and using them like real-life blueprints.

Stay tuned — because this is where C starts feeling like mini OOP! 😄

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✍️ Written with love by the ProgVeda Team — making C fun, one byte at a time!