Just PHP Fun #001.

addLetters.php

<?php
# https://www.codewars.com/kata/5d50e3914861a500121e1958 Alpabetical Addition.
function addLetters(...$letters) {
  if(empty($letters)) return 'z';
  $digits = array_map(
    function($x){ return ord($x) - ord('a') + 1;},
    $letters
  );
  $val = array_sum($digits)%26;
  if(0 == $val) return 'z';
  return chr(ord('a') - 1 + $val);
}

description.md

Just PHP FUN 001.

• https://www.codewars.com/kata/57a6633153ba33189e000074 Order count of characthers.
• https://www.codewars.com/kata/55fd2d567d94ac3bc9000064 Sum of odd numbers.
• https://www.codewars.com/kata/5d50e3914861a500121e1958 Alpabetical Addition.
• https://www.codewars.com/kata/59f7fc109f0e86d705000043 By 3, or not by 3? That is the question .
• https://www.codewars.com/kata/593c9175933500f33400003e Return the first M multiples of N.

Started at 18:06 19.05.2020 Tuesday May. Finished at 20:46 19.05.2020 Tuesday May. 2hrs 40 mintes. (Total time with chating, tea, and so on.)

divisibleByThree.php

<?php
# https://www.codewars.com/kata/59f7fc109f0e86d705000043 By 3, or not by 3? That is the question 
function divisibleByThree($str) {
  $x = array_reduce(
    str_split($str),
    function($acc,$v){
      return $acc + (int)$v;
    },
    0
  );
  return 0 == $x%3;
}

multiples.php

<?php
# https://www.codewars.com/kata/593c9175933500f33400003e Return the first M multiples of N.
function multiples(int $m, float $n): array {
  $answer = [];
  for($i = 1; $i<=$m; $i++) array_push($answer, $i*$n);
  return $answer;
}

orderedCount.php

<?php
# https://www.codewars.com/kata/57a6633153ba33189e000074 Order count of characthers.
function orderedCount($text) {
  if(empty($text)){
    return [];
  }
  $text = str_split($text);
  $h = [];
  foreach($text as $c){
    if(array_key_exists($c,$h)){
      $h[$c] += 1;
    }else{
      $h[$c] = 1;
    }
  }
  arsort($h);
  $ans = [];
  foreach($h as $k=>$v){
    array_push($ans,[$k,$v]);
  }
  
  return $ans;
}

rowSumOddNumbers.php

<?php
# https://www.codewars.com/kata/55fd2d567d94ac3bc9000064 Sum of odd numbers.
function rowSumOddNumbers($n) {
  if(1 == $n) return 1;
  $last =  ((1 + $n)*$n) - 1;
  $first = ((1 + $n-1) * ($n-1)) + 1;
  return (($last + $first) * $n)/2;
}