C – Language

Real-Life Examples of Variables in C

  1. Why Use Variables in Real Life?

In real programs, we use variables to store and manage data — such as a student’s details, product price, employee salary, etc.
Variables make it easy to update, calculate, and display data whenever needed.

🧩 Example 1: Student Data Program

Let’s create a program that stores information about a student and prints it.

Code:

#include <stdio.h>

int main() {

  // Student data

  int studentID = 15;

  int studentAge = 23;

  float studentFee = 75.25;

  char studentGrade = ‘B’;

 

  // Print variables

  printf(“Student ID: %d\n”, studentID);

  printf(“Student Age: %d\n”, studentAge);

  printf(“Student Fee: %f\n”, studentFee);

  printf(“Student Grade: %c”, studentGrade);

 

  return 0;

}

✅ Output:

Student ID: 15

Student Age: 23

Student Fee: 75.250000

Student Grade: B

🔹 2. Explanation

Variable

Type

Description

Example Value

studentID

int

Unique number to identify the student

15

studentAge

int

Student’s age

23

studentFee

float

Student’s course fee (decimal value)

75.25

studentGrade

char

Grade in a subject

‘B’

 

🧩 Example 2: Calculate the Area of a Rectangle

Let’s create a program that calculates the area using length × width.

Code:

#include <stdio.h>

int main() {

  // Create integer variables

  int length = 4;

  int width = 6;

  int area;

  // Calculate the area of a rectangle

  area = length * width;

  // Print the variables

  printf(“Length is: %d\n”, length);

  printf(“Width is: %d\n”, width);

  printf(“Area of the rectangle is: %d”, area);

  return 0;

}

✅ Output:

Length is: 4

Width is: 6

Area of the rectangle is: 24

  1. Explanation

Variable

Description

Example

length

Rectangle’s length

4

width

Rectangle’s width

6

area

Result of length × width

24

📘 Formula Used:
[
\text{Area} = \text{Length} \times \text{Width}
]

Quick Summary

Concept

Example

Description

Store details

Student info program

Real-life data storage

Perform calculations

Rectangle area

Use math operations

Print output

printf()

Display result