Week 1: Introduction to C Programming

Overview

Welcome to your first week of learning C programming! This week, we will cover the basics of writing and running a simple C program. By the end of this tutorial, you will:

• Understand the structure of a C program
• Learn how to use printf() for output
• Take user input using scanf()
• Work with basic data types and variables

Time Breakdown

• Introduction & Explanation (10 min)
• Writing a Simple C Program (10 min)
• Working with Variables and Data Types (15 min)
• Taking User Input (20 min)
• Exercise & Q/A (15 min)

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1. Writing Your First C Program (10 min)

A C program consists of functions and statements enclosed in {}. Every program starts with a main() function. Below is a simple C program that prints “Hello, World!” to the screen.

Example: Hello, World!

#include <stdio.h>

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

Explanation:

• #include <stdio.h>: This is a preprocessor directive that includes the standard input-output library.
• int main(): This is the main function where program execution starts.
• printf("Hello, World!\n");: This prints “Hello, World!” to the screen.
• return 0;: Ends the program successfully.

Exercise 1 (5 min):

Modify the above program to print your name instead of “Hello, World!”.

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2. Variables and Data Types (15 min)

Variables are used to store data. In C, you must declare a variable before using it.

Common Data Types:

Data Type	Description	Example
int	Stores integers	int age = 25;
float	Stores decimal numbers	float pi = 3.14;
char	Stores a single character	char letter = 'A';

Example: Using Variables

#include <stdio.h>

int main() {
    int age = 20;
    float height = 5.9;
    char grade = 'A';

    printf("Age: %d\n", age);
    printf("Height: %.1f\n", height);
    printf("Grade: %c\n", grade);

    return 0;
}

Exercise 2 (10 min):

Create a program that declares variables for your name, age, and favorite number, then prints them.

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3. Taking User Input (20 min)

You can take input from the user using scanf().

Example: User Input

#include <stdio.h>

int main() {
    int age;
    printf("Enter your age: ");
    scanf("%d", &age);
    printf("You are %d years old.\n", age);
    return 0;
}

Exercise 3 (10 min):

Write a program that asks the user for their name and age, then prints a greeting message.

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4. Assignment (10 min): Medical Checkup Program

Inspired by previous assignments, let’s create a structured task:

Task: Write a C program that simulates a basic medical checkup. Your program should:

1. Ask the user for their age, gender (M/F), height (in meters), weight (in kg), blood type (A, B, or O), and body temperature.
2. Print all this information in a single printf() statement, using proper formatting.

Example Output:

You are 24 years old and your gender is "M".
Your height and weight are 1.74 m, 74.00 kg.
Your blood type is 'A'.
Your body temperature is 36.50 degrees Celsius.

Hints:

• Use printf() for output formatting.
• Use \n for line breaks and \t for spacing.
• Store values in variables and use %d, %f, and %c format specifiers accordingly.

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Summary & Wrap-Up (10 min)

This week, we covered:

• Writing a simple C program
• Using printf() for output
• Declaring variables and using data types
• Taking user input with scanf()

Next Week: Basic C Programming - Arithmetic Operations and Control Statements

Happy coding! 🚀