🔌Your plug to a curated collection of useful C Programming tutorials, snippets, and projects that you can understand in 30 seconds or less.

P.S: This repository is a work in progress

• Use Ctrl + F or command + F to search for a snippet.
• Contributions welcome, please read the contribution guide.

Motivation for this project The core goal of 30 seconds of C is to provide a public record of my journey to learn c programming. It's my goal to provide a quality resource for both beginners and advanced c progammers/developers. My initial motivation for creating this repository was to use it as a tool to document my journey at the 42 Silicon Valley - an engineering and programming. The contents of this repo are designed to help you write real time C programs on your own.

Integer

• int

Character

• char

Floating Point

• float
  
• Double

• enum

• pointer
• array
• structure
• union

• void

Purpose: This repo provides useful tips to understand how to achieve 100% at 42 Silicon Valley exams. A great developer like you 😎, however, should not just memorize the answers.

Create a program that takes a string, and displays the first 'a' character it encounters in it, followed by a newline. If there are no 'a' characters in the string, the program just writes a newline. If the number of parameters is not 1, the program displays 'a' followed by a newline.

$> ./aff_a "abc" | cat -e
a$
$> ./aff_a "dubO a POIL" | cat -e
a$
$> ./aff_a "zz sent le poney" | cat -e
$
$> ./aff_a | cat -e
a$

#include <unistd.h>

int	main(int argc, char **argv)
{
	if (argc != 2)
		write(1, "a", 1);
	else
	{
		while (*argv[1])
			if (*argv[1] == 'a')
			{
				write(1, "a", 1);
				argv[1]++;
				break;
			}
	}
	write(1, "\n", 1);
	return (0);
}

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Write a program that displays all digits in descending order, followed by a newline.

$> ./ft_countdown | cat -e
9876543210$
$>

#include <unistd.h>

int	main(void)
{
	char c;
	c = '9';
	while (c >= '0')
	{
		write(1, &c, 1);
		c--;
	}
	write(1, "\n", 1);
	return (0);
}

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Write a function that displays all digits in ascending order.

Your function must be declared as follows:

void ft_print_numbers(void);

#include <unistd.h>

int	main(void)
{
	char c;

	c = '0';
	while (c <= '9')
	{
		write(1, &c,1);
		c++;
	}
	write(1, "\n", 1);
	return (0);
}

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If you are new to C Programming, try taking a look at some of these references.

• ANSI 89 – American National Standards Institute, American National Standard for Information Systems Programming Language C, 1989.
• Kernighan 78 – B. W. Kernighan and D. M. Ritchie, The C Programming Language, Prentice-Hall: Englewood Cliffs, NJ, 1978. Second edition, 1988.
• Thinking 90 – C* Programming Guide, Thinking Machines Corp. Cambridge Mass., 1990.
• Head First C - A complete learning experience for C and structured imperative programming.

• GeeksforGeeks - A computer science portal for geeks.
• SoloLearn - C Tutorial
• C Programming Google+ Community

• C Tutor - Visualize C code execution to learn C online
• Ideone - An nline compiler and debugging tool
• SoloLearn - Code Playground

The idea behind 30 Seconds of C was inspired some people who created similar collections in other programming languages and environments. Here are the ones we like the most:

• 30 Seconds of Code by charlarangelo
• 30 Seconds of CSS by atomiks
• 30 Seconds of Python by kriadmin
• 30 Seconds of Interviews by fejes713

Do you have a cool idea for a new snippet, or want to add your own tips? Checkout contributing.md.

<sub>Fred Siika

Grace Nelore</sub>

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