Activity: Programming in C Lab

Multi-session hands-on C programming practice with interactive tools

Grade XI • Computer Science ⏱️ Multi-Session

Brief Intro — Programming in C Lab

Reading about code is helpful, but the only way to truly master programming is by rolling up your sleeves and writing it yourself. This multi-session lab provides a structured path for you to practice everything from basic input/output to complex logic and data storage.

In this activity, you'll build your skills through hands-on tasks that cover C fundamentals, control structures, and array manipulation, giving you the practical experience needed to create your own applications.

Prerequisites

Basic understanding of programming concepts from Pair 1
Familiarity with algorithm and flowchart basics
Logical reasoning and problem-solving ability

Objectives

Master C program structure and basic I/O operations
Understand data types, format specifiers, and escape sequences
Apply various operators with correct precedence
Implement decision control structures (if-else, switch)
Use loop structures (while, do-while, for) effectively
Work with arrays (1D and 2D) for data storage
Manipulate strings using library functions
Utilize mathematical library functions

Session 1: Fundamentals, I/O & Variables

Every C program follows a standard structure, using data types and basic input/output functions to communicate with the user.

C Program Structure

A C program has a standard layout including preprocessor directives, the main() function, and variable declarations.

#include <stdio.h>

int main(void) {
    printf("Hello, World\n");
    return 0;
}

Data Types & Format Specifiers

Data Type	Description	Format Specifier	Size (Typical)
int	Integer (whole numbers)	%d or %i	4 bytes
float	Single-precision floating point	%f	4 bytes
double	Double-precision floating point	%lf	8 bytes
char	Single character	%c	1 byte

Task 1.1: Basic I/O

Write a program to display an integer, a float, and a double value stored in different variables. Then, modify it to take these values from the user using scanf().

Hint

Declare int a; float b; double c;. Use scanf("%d %f %lf", &a, &b, &c); and then print them back.

Task 1.2: Character & ASCII

Take a character from the user and print both the character and its corresponding ASCII value.

Hint

Use %c to read/print the character and %d to print its integer (ASCII) value.

Task 1.3: Variable Sizes (sizeof)

Write a program to check the size of different variables (short, long, long long, long double) using the sizeof() operator.

Hint

Use printf("Size: %d", sizeof(variable_name));

Task 1.4: Formula-Based Calculations

Implement the following calculations based on user input:

Simple Interest: I = (P * T * R) / 100
Area: Rectangle (L * B), Circle (3.14 * r * r)
Volume: Cube (L * L * L)
Temperature: Fahrenheit to Celsius [C = (F - 32) * 5/9]
Square: Calculate the square of an entered number

Session 2: Operators & Logic

Operators are the tools for mathematical, relational, and logical manipulation of data.

Interactive Simulator: C Expression Evaluator

Select an operator and enter values to see how C evaluates the expression.

Select Operator:

Operand 1: Operand 2:

Click Evaluate to see the result

Task 2.1: Arithmetic & Modulus

Take two integers from the user and perform all arithmetic operations (+, -, *, /, %).

Task 2.2: Increment/Decrement

Demonstrate the use of ++ and -- operators in both prefix and postfix forms.

Task 2.3: Swapping Logic

Write two programs to swap two numbers:

Using a third (temporary) variable.
Without using a third variable (Arithmetic method).

Hint (No third variable)

a = a + b; b = a - b; a = a - b;

Task 2.4: Selection Logic

Practice logical decision making:

Display the greater of two numbers using the conditional operator (?:).
Find the greatest of three numbers using nested logic.
Test whether an entered integer is positive or negative.

Session 3: Control Structures (Selection & Iteration)

Control structures give your program the intelligence to make choices and the power to repeat tasks efficiently.

Task 3.1: Switch Case

Write two programs using switch case:

Input a number (1-7) and display the corresponding Day of the Week.
Check whether an entered alphabet is a vowel or a consonant.

Task 3.2: Even/Odd Logic

Write a program to find if an entered integer is odd or even using if-else.

Task 3.3: Loop Ranges & Sums

Practice different loop ranges and accumulations:

Print natural numbers up to 50.
Find the sum of natural numbers between 10 and 20.
Find the sum of odd numbers between 50 and 100.
Find the sum of numbers in any user-defined range.

Task 3.4: Multiplications & Power

Use a for loop to:

Print the multiplication table of an entered number.
Find the power of a number (e.g., a^b) without using pow().

Task 3.5: Pattern Printing

Write programs to print the following shapes using nested loops:

A right-angled triangle of asterisks (*).
A solid rectangle shape of asterisks.

Session 4: Advanced Number Logic (Important Concepts)

Master these classic algorithms to sharpen your logical thinking and mathematical programming skills.

Task 4.1: Mathematical Properties

Implement logic to process the digits of a number:

Find the reverse of an entered number.
Check if a number is a palindrome (reads the same forward and backward).
Count the digits of an entered number.
Find the sum of digits (e.g., 123 -> 1+2+3=6).

Task 4.2: Classical Algorithms

Solve these cornerstone programming problems:

Factorial: Find the factorial of a number (n!).
Fibonacci Series: Print the series up to ten terms (0, 1, 1, 2, 3, 5...).
Armstrong Number: Check if sum of cubes of digits equals the number (e.g., 370).
Prime Number: Determine if a number is prime (only divisible by 1 and itself).
Factors: Display all factors of an entered number.

Session 5: Arrays (1D & 2D)

Arrays allow you to store and manage collections of data efficiently using indexed memory locations.

Task 5.1: 1D Array Operations

Practice common array tasks:

Store 10 elements in an array and print them.
Read n values and display them in reverse order.
Calculate the sum of all elements in an array.
Find the maximum element in an array.
Copy elements from one array into another array.

Task 5.2: 2D Array Operations

Work with matrices:

Declare a 3x3 matrix, input elements, and print it in grid format.
Write a program to perform addition of two matrices of the same size.

Session 6: Strings & Library Functions

Strings are character arrays with special handling in C, supported by a rich set of library functions.

Task 6.1: String Library Functions

Use string.h functions to:

Input a string and print it back.
Find the length of a string using strlen().
Compare two strings using strcmp().
Copy one string to another using strcpy().
Print a string in reverse and check if it is a palindrome.

Task 6.2: Manual String Handling

Re-implement library logic without using string.h:

Find string length using a while loop.
Copy one string to another manually.

Hint

Iterate until you encounter the null character '\0'.

Task 6.3: Math Library Demo

Write a program that uses math.h to demonstrate sqrt(), pow(), and abs().

Lab Summary (55 Questions Covered)

Basic I/O & Variable handling (Int, Float, Double, Char)
ASCII values and character data type
Memory sizing with sizeof() operator
Arithmetic, Logical, and Relational operators
Swapping logic (with/without temp variable)
Selection logic using if-else and switch
Iteration using for, while, and do-while
Mathematical concepts: Reverse, Palindrome, Sum of Digits
Cornerstone algorithms: Factorial, Fibonacci, Armstrong, Prime
1D Arrays: Searching, Summing, Reversing, and Copying
2D Arrays: Matrix input, display, and addition
String manipulation: Library vs. Manual handling
Formula implementation: Area, Volume, Interest, Temperature

Ready to test your knowledge?

Take the Assessment →