Introduction to Structures in C

Table of Contents:

1. Introduction


2. Defining and Declaring Structures


3. Accessing Structure Members


4. Nested Structures


5. Typedef for Structures


6. Simple Programs with Structures


7. Conclusion

1. Introduction:

In C programming, structures provide a way to group multiple variables of different data types into a single unit.
It allows us to create user-defined data types that can hold various pieces of information related to a particular
entity. Structures play a crucial role in organizing and managing data efficiently. This post will introduce you to
the concept of structures in C, explaining their syntax, usage, and benefits.

2. Defining and Declaring Structures:

In C, we define a structure using the struct keyword, followed by the structure name and a set of
curly braces enclosing the members of the structure. Each member is defined with a data type and an identifier.

// Defining a structure
struct Student {
    char name[50];
    int rollNumber;
    float marks;
};

3. Accessing Structure Members:

We can access the members of a structure using the dot (.) operator. This allows us to read or modify
the individual data elements within the structure.

// Declaring a structure variable and accessing members
struct Student student1;
strcpy(student1.name, "John Doe");
student1.rollNumber = 101;
student1.marks = 85.5;

4. Nested Structures:

Structures can be nested within each other, allowing us to create more complex data structures. This is especially
useful when dealing with hierarchical data.

// Nested structures example
struct Address {
    char street[100];
    char city[50];
    char state[50];
};

struct Contact {
    char phone[15];
    struct Address address;
};

// Accessing nested structure members
struct Contact person;
strcpy(person.phone, "123-456-7890");
strcpy(person.address.street, "123 Main St");
strcpy(person.address.city, "New York");
strcpy(person.address.state, "NY");

5. Typedef for Structures:

We can use the typedef keyword to create an alias for a structure. This simplifies the declaration of
structure variables.

// Using typedef for a structure
typedef struct {
    int x;
    int y;
} Point;

// Declaring and accessing a typedef structure variable
Point p1;
p1.x = 10;
p1.y = 20;

6. Simple Programs with Structures:

Let's explore a couple of simple programs to illustrate the practical usage of structures.

Program 1: Calculating Average Marks

#include <stdio.h>

struct Student {
    char name[50];
    float marks;
};

int main() {
    struct Student students[3];
    float totalMarks = 0;

    for (int i = 0; i < 3; i++) {
        printf("Enter name for student %d: ", i + 1);
        scanf("%s", students[i].name);

        printf("Enter marks for student %d: ", i + 1);
        scanf("%f", &students[i].marks);

        totalMarks += students[i].marks;
    }

    float averageMarks = totalMarks / 3;
    printf("Average marks: %.2f\n", averageMarks);

    return 0;
}

Program 2: Storing Employee Details

#include <stdio.h>

struct Employee {
    char name[50];
    int employeeID;
    float salary;
};

int main() {
    struct Employee employee1;
    printf("Enter employee name: ");
    scanf("%s", employee1.name);

    printf("Enter employee ID: ");
    scanf("%d", &employee1.employeeID);

    printf("Enter employee salary: ");
    scanf("%f", &employee1.salary);

    printf("\nEmployee Details:\n");
    printf("Name: %s\n", employee1.name);
    printf("ID: %d\n", employee1.employeeID);
    printf("Salary: %.2f\n", employee1.salary);

    return 0;
}

7. Conclusion:

In this post, we learned about structures in C, a powerful feature that enables us to create custom data types to
organize and manipulate related information. Structures help us manage complex data efficiently, making our code
more organized and readable. As you continue your C programming journey, understanding structures will be crucial
for tackling various real-world programming challenges.

Experiment with structures, and you'll find that they are fundamental to mastering C programming and data handling.
Happy coding!