🛠️ Lesson 2: Setup & Your First Program

⏱️ Estimated time: 20 minutes | Difficulty: Beginner

Setting Up Your C Environment

Unlike Python, C is a compiled language. You need a compiler to convert your C code into an executable program your computer can run.

Step 1: Install a Compiler

sudo apt-get install gcc

xcode-select --install

Step 2: Verify Installation

gcc --version
# Should show something like: gcc (GCC) 13.2.0

Step 3: Choose a Code Editor

• 📝 VS Code (Recommended) — Free, extensions for C
• 📝 Code::Blocks — Built-in compiler and debugger
• 📝 Notepad++ — Lightweight text editor

Your First C Program

Create a file called hello.c and type this:

#include <stdio.h>

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

Let's Break It Down Line by Line:

• #include <stdio.h> — Includes the Standard Input/Output library (gives us printf)
• int main() — The main function where your program starts. Every C program must have one!
• printf("Hello, World!\n") — Prints text to the screen. \n means new line
• return 0; — Tells the operating system "I finished successfully"
• { } — Curly braces define a block of code

Compiling & Running

# Step 1: Compile
gcc hello.c -o hello

# Step 2: Run
./hello          # Linux/Mac
hello.exe        # Windows

# Output: Hello, World!

More Examples

#include <stdio.h>

int main() {
    printf("My name is GK Solutions\n");
    printf("I am learning C programming!\n");
    printf("2 + 3 = %d\n", 2 + 3);  // %d prints an integer
    return 0;
}