Cortical Notes

Welcome to Cortical Notes! This blog is where I plan to explore math, science, and the occasional deep dive into technical topics. Today, I'm kicking things off with a programming classic: the C programming language.

Why start with C? C is a foundational language that provides direct access to the workings of a computer. It's widely used in system programming, embedded systems, and applications requiring high performance. Understanding C gives you insight into how computers execute code and manage resources like memory and processing.

What Makes C Special?

Direct Hardware Interaction: C provides low-level access to memory and hardware through constructs like pointers and manual memory management. This is a core reason why C is often used for operating systems and embedded development.

Efficiency: Compiled C code is close to machine code, making it incredibly fast and lightweight. Unlike interpreted languages, C code runs directly on the hardware, bypassing virtual machines or interpreters.

Cross-Platform Portability: C programs can be written once and compiled on nearly any platform with minimal modifications, thanks to its standardized libraries.

Writing Your First C Program

Here's the quintessential "Hello, World!" program, which demonstrates basic structure and syntax:

hello.c

1#include <stdio.h>
2
3int main() {
4    printf("Hello, World!\n");
5    return 0;
6}

Breaking It Down

Code Structure

#include <stdio.h>: Includes the Standard Input/Output library int main(): The program's entry point printf(): Prints text to the console return 0: Indicates successful execution

Understanding Variables and Data Types

C is a statically-typed language, meaning variables must be declared with their types. Here's an example:

variables.c

1#include <stdio.h>
2
3int main() {
4    int age = 25;           // Integer type
5    float height = 5.9;     // Floating-point type
6    char initial = 'A';     // Character type
7
8    printf("I am %d years old, %.1f feet tall, and my initial is %c.\n", age, height, initial);
9    return 0;
10}

Format Specifiers

%d: for integers %.1f: for floating-point numbers %c: for characters

Memory Management: What Happens Behind the Scenes

When you declare a variable in C, the compiler allocates memory for it. For example:

1int number = 10;

This tells the compiler to allocate 4 bytes of memory (on most modern systems) to store the integer value 10. Memory in C is closely tied to the system's architecture, and understanding this is essential when working with pointers and dynamic memory allocation.

C Programming Language concept illustration — C: The foundation of modern programming

C is a foundational language that provides direct access to the workings of a computer. It's widely used in system programming, embedded systems, and applications requiring high performance. Understanding C gives you insight into how computers execute code and manage resources like memory and processing.

Memory Management: A Key Concept

memory.c

1#include <stdio.h>
2#include <stdlib.h>
3
4int main() {
5    int *numbers = malloc(5 * sizeof(int));
6    if (numbers == NULL) {
7        return 1;
8    }
9    
10    for(int i = 0; i < 5; i++) {
11        numbers[i] = i + 1;
12    }
13    
14    free(numbers);
15    return 0;
16}

Memory Safety

Always check malloc's return value and free allocated memory to prevent memory leaks.

Loops and Control Flow

Control structures like loops allow you to automate repetitive tasks. Here's an example of a for loop:

loops.c

1#include <stdio.h>
2
3int main() {
4    for (int i = 1; i <= 5; i++) {
5        printf("Count: %d\n", i);
6    }
7    return 0;
8}

This outputs:

Count: 1
Count: 2
Count: 3
Count: 4
Count: 5

Behind the scenes, the compiler translates this into machine code, iterating through memory locations to execute the loop instructions efficiently.

Why Should You Learn C in 2025?

While newer languages like Python or JavaScript simplify programming, C offers unique insights into how computers function:

Key Benefits of Learning C

• Bindings to Low-Level Code: Direct hardware interaction • Manual Memory Management: Complete control over resource allocation • Performance Optimization: Unparalleled speed and efficiency

A Challenge for You

Try modifying the "Hello, World!" program to include a personalized message. Once you're comfortable, experiment with variables and loops. Here's a hint:

Input Safety

When using scanf, always limit input size to prevent buffer overflows!

challenge.c

1#include <stdio.h>
2
3int main() {
4    char name[50];
5
6    printf("What is your name? ");
7    scanf("%49s", name); // Limits input to 49 characters
8
9    printf("Hello, %s! Welcome to C programming.\n", name);
10    return 0;
11}

Final Thoughts

C is more than a programming language; it's a tool to understand how software communicates with hardware. By learning C, you gain a deeper appreciation for the intricacies of computation and develop skills that are transferable across many domains. Stick with it, and you'll build a strong foundation for tackling any technical challenge.

That's it for today. Let me know what topics in math, science, or programming you'd like to explore next. Let's dig deep together, one note at a time.

Why Learn C? An Introduction to the Basics of Programming