Lesson 9 - How to Write and Execute Your First C Program: Printing a "Hello" Message

Lesson No 9 Algorithm Development in C Programming

Welcome to this step-by-step guide on writing and executing your first C program. In this tutorial, we will walk through the process of creating a simple C program that prints the message "Hello" to the console. By the end of this article, you will have the knowledge and skills to write, compile, and run your first C program, laying the foundation for your journey into the world of computer programming.

Step 1: Understanding the Basics of C Programming

C is a powerful and versatile programming language that has been widely used for decades in a variety of applications, from system programming to game development. It is known for its efficiency, low-level control, and portability, making it a popular choice for developers working on a wide range of projects.

Before we dive into writing our first C program, it's important to understand the fundamental structure and components of a C program. A C program typically consists of one or more functions, which are blocks of code that perform specific tasks. The main function, denoted by the keyword "main()", is the entry point of the program and is where the execution begins.

Step 2: Preparing Your Development Environment

To write and execute your first C program, you will need a C compiler. A compiler is a software tool that translates the human-readable C code into machine-readable instructions that the computer can understand and execute.

There are several popular C compilers available, such as GCC (GNU Compiler Collection) and Microsoft Visual C++. For this tutorial, we will be using GCC, as it is a widely used, free, and cross-platform compiler.

Once you have a C compiler installed, you can proceed to the next step of writing your first C program.

Step 3: Writing the C Program

Open a text editor and create a new file. This file will contain the source code for your C program. The standard file extension for C source code is ".c", so let's name our file "hello.c".

In the "hello.c" file, type the following code:

#include <stdio.h>
int main() {
    printf("Hello\n");
    return 0;
}

Let's break down the code:

• #include <stdio.h>: This line includes the standard input/output library, which provides functions for reading and writing to the console.
• int main() {: This is the main function, which is the entry point of the program.
• printf("Hello\n");: This line uses the printf() function from the stdio.h library to print the message "Hello" to the console. The \n at the end of the string represents a newline character, which will move the cursor to the next line.
• return 0;: This line indicates that the program has executed successfully and returns a value of 0 to the operating system.

Step 4: Compiling the C Program

Now that you have written the C program, it's time to compile it. Open a terminal or command prompt and navigate to the directory where you saved the "hello.c" file.

In the terminal, type the following command to compile the program:

gcc -o hello hello.c

This command uses the GCC compiler to compile the "hello.c" file and create an executable file named "hello".

Step 5: Executing the C Program

Once the compilation is successful, you can execute the program by typing the following command in the terminal:

./hello

This command will run the "hello" executable file, and you should see the output "Hello" printed to the console.

Congratulations!

You have successfully written, compiled, and executed your first C program. This is a significant milestone in your journey as a C programmer, and it lays the foundation for more complex programs you will create in the future.

Remember, the key to becoming proficient in C programming is practice. Continue to write more programs, experiment with different features and functions, and challenge yourself to solve increasingly complex problems. With dedication and persistence, you will quickly become a skilled C programmer.

If you have any questions or encounter any issues while working through this tutorial, don't hesitate to reach out to the programming community for support. There are many online resources, forums, and communities dedicated to helping beginners and experienced programmers alike.

Happy coding!