Defining and Declaring Structures in C

Table of Contents

1. Introduction to Structures


2. Structure Definition


3. Structure Declaration


4. Accessing Structure Members


5. Initializing Structures


6. Simple Programs with Structures


7. Conclusion

1. Introduction to Structures

In C programming, a structure is a user-defined data type that allows you to group different types of variables together. Structures are useful when you want to represent a complex data structure with multiple components. Each component within a structure is called a member.

2. Structure Definition

To define a structure, you use the struct keyword followed by the structure tag name and a list of member variables enclosed in curly braces.

struct Person {
    char name[50];
    int age;
    float height;
};

In the above example, we have defined a structure Person with three members: name, age, and height.

3. Structure Declaration

After defining a structure, you can declare variables of that structure type.

struct Person person1;
struct Person person2;

4. Accessing Structure Members

You can access the members of a structure using the dot (.) operator.

struct Person person1;
strcpy(person1.name, "John");
person1.age = 25;
person1.height = 175.5;

5. Initializing Structures

You can initialize a structure at the time of declaration using curly braces.

struct Person person1 = {"Alice", 30, 162.0};

6. Simple Programs with Structures

Program 1: Adding Two Complex Numbers

#include <stdio.h>

struct Complex {
    float real;
    float imag;
};

int main() {
    struct Complex num1, num2, sum;

    printf("Enter real and imaginary part of first complex number: ");
    scanf("%f %f", &num1.real, &num1.imag);

    printf("Enter real and imaginary part of second complex number: ");
    scanf("%f %f", &num2.real, &num2.imag);

    sum.real = num1.real + num2.real;
    sum.imag = num1.imag + num2.imag;

    printf("Sum = %.2f + %.2fi", sum.real, sum.imag);
    return 0;
}

This program adds two complex numbers using a structure called Complex. The user is prompted to enter the real and imaginary parts of both numbers, and the program calculates their sum and displays it.

Program 2: Storing Employee Information

#include <stdio.h>

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

int main() {
    struct Employee emp1;

    printf("Enter employee name: ");
    scanf("%s", emp1.name);

    printf("Enter employee ID: ");
    scanf("%d", &emp1.emp_id);

    printf("Enter employee salary: ");
    scanf("%f", &emp1.salary);

    printf("Employee Details:\n");
    printf("Name: %s\n", emp1.name);
    printf("ID: %d\n", emp1.emp_id);
    printf("Salary: %.2f\n", emp1.salary);

    return 0;
}

This program demonstrates the usage of structures to store employee information. The user is asked to enter the employee's name, ID, and salary, and the program displays the entered details.

7. Conclusion

In this post, we learned about defining and declaring structures in C. Structures provide an efficient way to organize data and represent complex entities in programming. By grouping variables together, you can create more organized and readable code. Understanding structures is a fundamental concept for anyone starting with C programming.

Experiment with structures in your programs and explore their versatility in handling various data types. With practice, you will become proficient in using structures to manage data effectively in C programming. Happy coding!