DEV Community: Farhad

Convert string to camel case CodeWars Kata

Farhad — Wed, 12 May 2021 14:14:43 +0000

Codewars

Codewars is a platform that helps you learn, train, and improve your coding skills by solving programming tasks of many types and difficulty levels. Here is the first Kata I've solved here, and I would like to share my solutions here in DEV.

What is a Kata?

On Codewars, kata is code challenges focused on improving skill and technique.

❓ Here is my first Kata:

Link to the Kata

Write a method/function so that it converts dash/underscore delimited words into camel casing. The first word within the output should be capitalized only if the original word was capitalized (known as Upper Camel Case, also often referred to as Pascal case).

Examples

"the-stealth-warrior" gets converted to "theStealthWarrior"
"The_Stealth_Warrior" gets converted to "TheStealthWarrior"

💡 We can use Regex to perform a search and replace in almost all programming languages.

A regular expression is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Regular expression techniques are developed in theoretical computer science and formal language theory.

View on Wikipedia

I used preg_replace_callback function in PHP which performs a regular expression search and replace using a callback to find "_\w" or "-\w" patters like _a or -b and replace them with the equivalent uppercase character. like _b => B so the-stealth will be theStealth.

💻 So, my solution in PHP is:

function toCamelCase($str){
    return preg_replace_callback('/(\-|\_)([a-z])/i', function ($match) {
        return strtoupper($match[2]);
    }, $str);
}

You might ask what is that $match[2], well here is the var_dump($match) output:

array(3) {
  [0]=>
  string(2) "_s"
  [1]=>
  string(1) "_" 
  [2]=>
  string(1) "s" 
}

as you see inside of each iteration this array contains, the matched string beside regex groups! in our case here we can access that group by $match[2]`.

Thank You ❤️

I wish my posts to be useful to anyone who's new to the world of programming or anybody who's curious 🧐!
If you find the content useful to you, please comment your thoughts, I would love to learn from you all.

Thank you for your loving directions.

Project Euler 002

Farhad — Sat, 08 May 2021 11:15:34 +0000

Hello DEV

Project Euler is a series of challenging mathematical/computer programming problems that I like to start. I'm sure there will be a lot to learn for me, and I would like to share my solutions here in DEV.

❓ Here is problem 002:

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

💡 For solving this problem, we can use a combination of the Modulo operation and also Addition.

❗ The first solution you might think of when working with Fibonacci sequence or other similar concepts in programming is for sure,
the recursive approach. but we always need to remember that these functions may be called a thousand times and this simply means
you will face one of those Maximum call stack size exceeded like errors!

This happens because of 💀 the space complexity of these algorithms (Have a 👀 at this article on this topic), so I use the Iterative approach instead here.

This is the formula for the Fibonacci sequence:

fib(n) = fib(n-1) + fib(n-2) → for n > 1
fib(n) = 1 → for n = 0, 1

we can suppose we have these variables:

MAX = 4000000

first_number = 1
second_number = 1

sum = 0

then we calculate the answer by calculating every next term by its previous terms that we simply store in 2 different variables!
and then filtering out the even numbers and summing them all up.

💻 So, my solution in Python is:

while second_number <= MAX:
    temp = second_number
    second_number += first_number
    first_number = temp

    if second_number % 2 == 0:
        sum += second_number
print(sum)

This might not be the best answer to this problem, but it only calculates 32 numbers (odd numbers also included) for this problem,
which is much better than the recursive approach. clearly if you be able to find a way not calculating the odd numbers at all! that
will be a perfect improvement, Can't wait to see if you have any ideas about this.

✅ The answer to this problem is 4613732.

Thank You ❤️

I wish my posts to be useful to anyone new to the world of programming or anybody curious 🧐!
If you find the content useful to you, please comment your thoughts, I would love to learn from you all.

Thank you for your loving directions.

Project Euler 001

Farhad — Fri, 07 May 2021 13:52:21 +0000

Hey folks

❓ Here is problem 001:

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6, and 9. The sum of these multiples is 23.
Find the sum of all the multiples of 3 or 5 below 1000.

💡 For solving this problem, we can simply use the Modulo operation and calculate the numbers which are multiples of 3 or 5.

❗ Modulo is a math operation that finds the remainder when one integer is divided by another. In writing, it is frequently abbreviated as a mod, or represented by the symbol %.
For two integers a and b:
a mod b = r
Where a is the dividend, b is the divisor (or modulus), and r is the remainder.

Here is an example:

11 mod 4 = 3, because 11 divides by 4 (twice), with 3 remaining.

💻 So, my solution in Python is:

sum = 0

for integer in range(1, 1000):
    if integer % 3 == 0 or integer % 5 == 0:
        sum += integer
print(sum)

✅ The answer to this problem is 233168.

Thank You ❤️

Thank you for your loving directions.

Tailwind CSS Window Mockup Light/Dark

Farhad — Sun, 27 Dec 2020 08:54:25 +0000

Hey there, 👋
Here is a Window Mockup built with tailwind CSS

⭐ I've also included the new Dark Mode feature in Tailwind, so you only need to add the dark class to the parent element or the HTML tag of your document to turn the dark mode on, you can also move the transition classes to yourHTML tag.

⚠ This behavior is triggered by using the class option in your tailwind config file, other methods are described in Documentation

// tailwind.config.js
module.exports = {
  darkMode: 'class',
  // ...
}

<div class="max-w-2xl transition-colors ease-linear shadow-md">
    <div class="w-full h-12 rounded-t-lg bg-gray-200 dark:bg-gray-900 flex justify-start items-center space-x-1.5 px-4">
        <span class="w-3 h-3 border-2 border-transparent dark:border-red-400 rounded-full bg-red-400 dark:bg-transparent "></span>
        <span class="w-3 h-3 border-2 border-transparent dark:border-yellow-400 rounded-full bg-yellow-400 dark:bg-transparent"></span>
        <span class="w-3 h-3 border-2 border-transparent dark:border-green-400 rounded-full bg-green-400 dark:bg-transparent"></span>
    </div>
    <div class="bg-gray-100 dark:bg-gray-700 border-t-0 w-full h-96 rounded-b-lg"></div>
</div>

Thank You ❤️

I wish my posts to be useful to anyone who's new to the world of web development, programming, or anybody who's curious 🧐!

If you find the content useful to you, please comment your thoughts, I would love to learn from you all.

Thank you for your loving directions.

Laravel Or Ruby on Rails 2021?

Farhad — Sat, 26 Dec 2020 18:40:08 +0000

Hey everyone,
I would like to know which framework will you choose for 2021 I have no exp with ruby and ruby on rails, I am amazed 🤩 by ruby's syntax but I kinda feel Laravel is more modern and popular. so, can you please inform me about its capabilities comparing with Laravel. Thanks, 🙏